Will a nuclear country use nuclear weapons if attacked by conventional means by another nuclear country?

Question

I am a learner of the Russian language and saw the following statement by a vice-president of the Russian Academy of Geopolitical Problems:

Скажу лишь то, что в условиях обычной войны, если на нас нападут без применения ядерного оружия, мы свою "ядерную дубинку" не применим. Как не применила во время Второй мировой войны другой вид оружия массового поражения, химическое, ни одна из воюющих стран. Все его имели в количестве, достаточном для того, чтобы просто залить им друг друга. Но никто этого не сделал, даже гибнущая нацистская Германия. Также и в случае с ядерным оружием. Ведь все отдают себе отчет в том, что его применение будет самоубийством. И о том, что мы его не применим в случае войны с обычными средствами, прекрасно знают и в НАТО, и в Китае. (Source)

My translation:

I will only say that we will not use our "nuclear stick" under conditions of conventional war, if we are attacked by conventional means, just as in WWII neither of the fighting countries used another kind of weapons of mass destruction, chemical weapons. Everyone had chemical weapons in amounts sufficient to flood each other, but no one did so, even the dying Nazi Germany. The same will happen with nuclear weapons, as everyone realizes that using them will be a suicide. Both the NATO and China are perfectly aware that we won't use nuclear weapons in case of conventional war.

My question: Do political scientists and experts agree with the view that if a conventional war breaks out between two major nuclear countries or alliances, which possess strategic nuclear weapons and a second-strike capability, the fighting sides will refrain from using nuclear weapons of mass destruction no matter what, just as Nazi Germany refrained from using chemical weapons in WWII?

My doubts come from the following consideration. Let's suppose two major nuclear countries are in conventional war against each other and that one of them is losing the war. What if the losing side starts using its nuclear weapons of mass destruction in a limited way (i.e., tactical use against the enemy's military forces and/or limited strikes to the enemy's territory and civil population)? The other side will then face a choice between (i) responding with a full-scale nuclear strike (leading to a mutual destruction), (ii) trading limited nuclear blows, and (iii) agreeing to stop the war. I guess that Option (i) will be unacceptable for the winning country. If the winning country chooses Option (ii), I guess the losing country can increase the magnitude of limited nuclear strikes to the extent sufficient to force the winning country to agree to stop the war. So it appears that nuclear weapons are a factor even in a conventional war, as the losing side is apparently able to stop the war at any moment by using nuclear weapons of mass destruction in a limited way or perhaps even by threatening to do so.

I am curious as to what is the dominating view by experts on this.

Answer 1

Except China nobody has currently pledged this, and even the Chinese pledge is not considered credible (by some Western experts, at least):

Most states with nuclear weapons maintain policies that would permit their first use in a conflict. Pledges to only use these weapons in retaliation for a nuclear attack—or a no-first-use (NFU) policy—are rare. Where these pledges have been made by nuclear states, their adversaries generally consider them not credible.

A so-called NFU pledge, first publicly made by China in 1964, refers to any authoritative statement by a nuclear weapon state to never be the first to use these weapons in a conflict, reserving them strictly to retaliate in the aftermath of a nuclear attack against its territory or military personnel. These pledges are a component of nuclear declaratory policies. As such, there can be no diplomatic arrangement to verify or enforce a declaratory NFU pledge, and such pledges alone do not affect capabilities. States with such pledges would be technically able to still use nuclear weapons first in a conflict, and their adversaries have generally not trusted NFU assurances. Today, China is the only nuclear weapon state to maintain an unconditional NFU pledge.

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Even post-cold-war US doctrine didn't rule out a preemptive strike or tactical use

The last nuclear operations doctrine, published during the George W Bush administration in 2005, also caused alarm. It envisaged pre-emptive nuclear strikes and the use of the US nuclear arsenal against all weapons of mass destruction, not just nuclear.

It was apparently formally cancelled in Feb 2006.

The revised draft included for the first time descriptions of preemptive use of US nuclear weapons, and caused the Senate Armed Services Committee to ask for a briefing, and 16 lawmakers to protest to President Bush.

The decision to cancel the doctrine document, and four other related documents, was confirmed today [2 Feb 2006] by the Pentagon.

And more recently (under Trump), the Pentagon has published and then retracted from public view a somewhat similar document.

The document, entitled Nuclear Operations, was published on 11 June [2019], and was the first such doctrine paper for 14 years. Arms control experts say it marks a shift in US military thinking towards the idea of fighting and winning a nuclear war – which they believe is a highly dangerous mindset.

“Using nuclear weapons could create conditions for decisive results and the restoration of strategic stability,” the joint chiefs’ document says. [...]

The Nuclear Operations document was taken down from the Pentagon online site after a week, and is now only available through a restricted access electronic library. [...] A spokesman for the joint chiefs of staff said the document was removed from the publicly accessible defence department website “because it was determined that this publication, as is with other joint staff publications, should be for official use only”.

And most notably during the Cold War:

In most cases, these [tactical nuclear] weapons were deployed to defend U.S. allies against aggression by the Soviet Union and its Warsaw Pact allies, but the United States did not rule out their possible use in contingencies with other adversaries. In Europe, these weapons were a part of NATO’s strategy of “flexible response.” Under this strategy, NATO did not insist that it would respond to any type of attack with nuclear weapons, but it maintained the capability to do so and to control escalation if nuclear weapons were used. This approach was intended to convince the Soviet Union and Warsaw Pact that any conflict, even one that began with conventional weapons, could result in nuclear retaliation. As the Cold War drew to a close, NATO acknowledged that it would no longer maintain nuclear weapons to deter or defeat a conventional attack from the Soviet Union and Warsaw Pact because “the threat of a simultaneous, full-scale attack on all of NATO’s European fronts has effectively been removed.” But NATO documents indicated that these weapons would still play an important political role in NATO’s strategy by ensuring “uncertainty in the mind of any potential aggressor about the nature of the Allies’ response to military aggression.

The above para is a pretty simplistic presentation of the US Cold War position (and mostly reflects the McNamara years). For a much more nuanced historical presentation that follows all the changes in doctrine see Nichols et al. "Tactical Nuclear Weapons and NATO".

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And Russia did not shy from this view either:

In 1999, at a time when renewed war in Chechnya seemed imminent, Moscow watched with great concern as NATO waged a high-precision military campaign in Yugoslavia. The conventional capabilities that the United States and its allies demonstrated seemed far beyond Russia’s own capacities. And because the issues underlying the Kosovo conflict seemed almost identical to those underlying the Chechen conflict, Moscow became deeply worried that the United States would interfere within its borders.

By the next year, Russia had issued a new military doctrine whose main innovation was the concept of “de-escalation”—the idea that, if Russia were faced with a large-scale conventional attack that exceeded its capacity for defense, it might respond with a limited nuclear strike. To date, Russia has never publically invoked the possibility of de-escalation in relation to any specific conflict. But Russia’s policy probably limited the West’s options for responding to the 2008 war in Georgia. And it is probably in the back of Western leaders’ minds today, dictating restraint as they formulate their responses to events in Ukraine.

The exact text was (in translation)

The Russian Federation reserves the right to use nuclear weapons in response to the use of nuclear and other types of weapons of mass destruction against it and (or) its allies, as well as in response to large-scale aggression utilizing conventional weapons in situations critical to the national security of the Russian Federation.

The Russian Federation will not use nuclear weapons against states party to the Nonproliferation Treaty that do not possess nuclear weapons except in the event of an attack on the Russian Federation, the Russian Federation Armed Forces or other troops, its allies, or a state to which it has security commitments that is carried out or supported by a state without nuclear weapons jointly or in the context of allied commitments with a state with nuclear weapons.

Formally this represented a departure from the Soviet declarations...

Although the Soviet Union had pledged that it would not be the first to use nuclear weapons, most Western observers doubted that it would actually observe this pledge in a conflict. Instead, analysts argue that the Soviet Union had integrated nuclear weapons into its warfighting plans to a much greater degree than the United States. [...]

The Soviet Union reportedly began to reduce its emphasis on nuclear warfighting strategies in the mid-1980s, under Soviet President Mikhail Gorbachev. He reportedly believed that the use of nuclear weapons would be catastrophic.

Answer 2

At the height of the cold war, the primary threat considered by NATO was a Russian-led invasion of Western Germany. The Russians and their satellite states has a massive numbers advantage in armor and other conventional weapons. One of the conventional weapons designed to counter this threat was the A-10 plane, but this plane soon became obsolete as the Russians added mobile surface to air missile batteries to their armies.

As a result, NATO planned to use short-range nuclear weapons to stop such an invasion, chiefly by taking out the logistical support for such an invasion. Tanks are fairly small and fairly mobile, a nuclear weapon is not an effective weapon against them. But without diesel and ammo they soon come to a halt.

The Russian statement probably should be taken as a desire more than a conclusion.

Answer 3

I believe that when it comes to survival no option is off the table. Also, remember that even when survival is not threatened use of nuclear weapons is possible - see Hiroshima and Nagasaki.

I believe that when people think about a nuclear strike, they tend to imagine ICBMs flying overhead, releasing dozens of megaton warheads etc. Truth is a bit more detailed. Nuclear warhead does not need to be mounted on the ICBM and aimed at the opponent's capital to have an application on a modern battlefield.

During the Cold War, both Soviets and USA had artillery shells with nuclear warheads. Yields were as low as 0.3kT. There were nuclear air-to-air missiles designed to shot down entire squadrons of incoming enemy bombers. There are currently types of nuclear-capable torpedoes that are designed to take out entire battlegroups with one strike.

So, in case of a conflict between near-peer adversaries with the nuclear capability, it is quite conceivable that a losing side may employ a limited nuclear strike against a military target simply to 'remind' the other side that it will not surrender until all options are exhausted.

So-called 'tactical nuclear weapons' are meant to have a dual effect - destroy large enemy concentrations and remind the opponent that he is not engaging with a toothless opponent.

Whether tactical nuclear strike would lead to escalation is strongly dependent on the situation and impossible to predict. How hot the conflict will get will depend on how vital would be the interests that are fought over. In case of a total annihilation scenario total nuclear war is possible - that is why nuclear weapons are called 'deterrents'. They do not guarantee a lack of war (both USA and Russia are leading wars without the use of nuclear arsenal), they 'sort of' guarantee a lack of total war.

Answer 4

There has actually been a war between two nuclear powers, the Kargil War between India and Pakistan in 1999. Neither side used its nuclear weapons. So far, therefore, the score is 1-0 against a nuclear power using its nuclear weapons in a war with another nuclear power. It would probably be different if the war posed an existential threat to one of the participants, but relatively few wars actually do so.

Answer 5

If the conventional forces of a nuclear power are pouring across your border, and your own conventional forces can't stop them, then the only two choices are:

1. surrender, or
2. nuke them (either tactically, strategically, or both).

Given the size imbalance of NATO forces in Europe vs Warsaw Pact forces, and the distance US men & materiel have to travel in order to reinforce Europe, the only realistic scenario for one nuclear power nuking another would have been if Soviet/ComBlock forces poured across the Fulda Gap into West Germany.

NATO would have started nuking very quickly (unless the Sovs nuked first using Short and Intermediate Range Ballistic Missiles).

Answer 6

The USSR had a "Second Strike Only" policy that it claimed was for self-defense (and there's a good argument that self-defense was a necessity, given that the only other Nuclear Power at the time was legendary in its opposition to Communism). However, this was also a policy position to mask the fact that the Soviets never developed a reliable first strike weapon. The problem was that the fuel for their rockets was highly corrosive to the metal used to build the rockets. To avoid the obvious problems of a nuclear rocket melting, the rockets were only fueled if likely launch was imminent (The Americans on the other hand, had no such problem and could reliably store their missiles in silos, with a single exception where a rocket detonated (the warhead survived) in the silo). Because of this and the Soviet's own preference for keeping launch vehicles mobile, especially in the sparsely populated north and east of the nation and the highly centralized west (especially Moscow) and the strategic importance of Germany, the Soviets figured that the U.S. would launch a First Strike towards Moscow from the East (and with out ICBM range, Turkey was basically the U.S. Cuba. Or rather, Cuba was the Soviet Turkey since Cuba was in response to American Nukes in Turkey) and the political import of showing the U.S. as the bad actor, the Soviets never had a real need to develop a fuel for First Strike.

However, because of the corrosive nature of the fuel, the Soviets would usually "Fuel" the rockets in a build up to a possible exchange (this could take as long as six hours to both fuel and defuel and the Soviets could keep it fueled for three days at a time.). Modern films may pay a lip service line to the Soviets "fueling rockets" as an indicator that "it just got real." The Soviets also relied on deception and other tactics to keep the U.S. at bay. Back in the 50s and 60s, American political buzzwords included such things as "The Bomber Gap" and later "The Missile Gap" which referred to which side had more delivery vehicles (subs, the third and probably most deadly, part of the Nuclear Trifecta, weren't viable at this point). U.S. Politics were convinced that the gaps were not in their favor at these times. Meanwhile on the otherside of the Iron Curtain, the Soviets might not be aware of the actual numbers the U.S. had, but they certainly knew they were at the disadvantage, but strategically could fool their people and observers for a good while. For example, the Bomber Gap was hidden by May Day parades where the Soviets did fly overs with their bombers... and once they passed over the camera, they turned them around and took another flight... but the people on the ground were told it was a different wave of bombers. The Space Race was basically a public display of the rockets (On the U.S. side, until the Apollo program, all manned space flights were launched on rockets that were designed to carry nukes. The warheads were removed and a more friendly space capsule was screwed on. The Saturn V holds the distinction of being the first purpose built space rocket... it was designed to go to the moon, not to shoot Nukes at Earth). Again the Soviets were also trying to put things in space to say "if we can put a satellite/dog/man into space and bring it back, we can put a nuke in space and bring it down too." Of course, they didn't say what they were hiding. Sputnik was never designed to return, nor was Sputnik II which carried the dog Laika into space... and used a second identical dog that was claimed to be Laika. The first manned spaceflight by Yuri Gagarin wasn't technically a record breaking flight, as international rules for flight records automatically disqualify a pilot from claiming an achievement if the pilot does not land while inside the flight vehicle. The Vostok craft required its pilot to parachute out before impact into the ground. Of course, the Soviets' point wasn't about sticking the landing, but showing that they could crash something into anywhere they wanted... and in the grand scheme of things, Nukes tend to detonate before hitting the Earth.

Right now, most nuclear nations maintain a "No Second Strike" or "Limited First Strike" policy. Most of Nuclear NATO (U.S., U.K., France) are "Second Strike Only" as for two of them, Second Strike is only really viable to not getting Nuked by Russia when the Cold War goes hot. The U.S. has limited First Strike, but it was always after conventional defenses failed to keep the Warsaw Pact war machine out of Western Europe or the Middle East (and they were damn near ready to end the world over Nukes in Cuba... of all the close calls that nearly sent the cold war hot, half of them would occur during the Cuban Missile Crisis). The Soviets were maintained Seconds Strike both because they couldn't do a First Strike and because it made the U.S. the bad guys (to this date, the U.S. is the only nation to use nuclear weapons in war.). We discussed that this was more a matter of technological capability and not because it looked good.

China maintained a Second Strike only, as they were equally concerned over a U.S. and U.S.S.R. attack. India maintained Second Strike initially to keep the U.S. and U.S.S.R. policies out of India. Additionally, China had the Bomb already and both were not the best of neighbors. This turned into a nightmare for India when Pakistan got the bomb though Pakistan also maintains it is second strike only (and since they don't have a trifecta, it's more not much a promise. They'd have to use First Strike to hope to Counter a Second Strike from India). North Korea also maintains second strike only because they need a reason to keep most of the civilized world to put up with their nonsense and not decide to invade them and be done with it. That said, their nuclear arsenal is... well, lets just say the people of Hiroshima would have prefered to have an NK Nuke dropped on them than a U.S. one (if not having a nuclear bomb used on them was not an option. Basically, North Korea's bomb barely qualifies. That said, the nation highly overspends on the military).

There are a few outliers. South Africa joined the Nuclear Club in the early 1980s (early estimates could be in 1979, but that's still not certain). These were also for Second Strike deterrence because in the 1980s, nobody liked South Africa. In the 1990s, South Africa became the first (and only) Nuclear Nation in the world to disarm (voluntarily no less) and so there current policy is "no strike". It's believed they might have jointly worked with Israel on development. Israel's Nuclear policy is basically "I am shocked, shocked I tell you, that you would insinuate that we even have nuclear bombs. Our policy on their use is second strike" At which point someone in the press reminds the Israeli Minister of Defense that he's using the wrong eye to wink at his generals, at which point he reveals he had his fingers crossed the entire time and shouts "Just Kidding. Or am I? By the way, did you guys get my Casablanca reference?" Naturally the whole press conference is done in front of a rocket-shaped grain silo with a nuclear symbol painted on it (Translation: Israel maintains a refusal to confirm or deny if it has Nukes... except Nukes only work as a deterrence if the world knows you got them... so they deliberately lie badly. Everyone goes along with it because they want to be polite about how bad Israel is at lying. And apologies in advanced for the bit of humor in that, but I find when discussing the grim nature of nuclear weapons (especially coupled with Middle East Politics), sometimes a little humor is necessary and the open secret of Israel's status as a nuclear nation gives me a moment to be silly.).

Answer 7

Initiating a nuclear attack on another nuclear armed nation has consequences, because that other nation will retaliate in kind. Unless that nuclear strike takes out 100% of their capability, attacking another nuclear armed nations with nuclear weapons is essentially the same as attacking yourself with nuclear weapons.

This is the essence of deterrence, specifically the policy of Mutually Assured Destruction: to instill a sense of fear of retaliation in a potential opponent.

One also has to consider that nuclear bombs are very dirty, and tend to scatter radioactive particles into the atmosphere, where they can fall on another, uninvolved nation.

So, in addition to considering the retaliation from the opponent, one would also have to consider the reaction from uninvolved nuclear armed states that can suffer from the fallout. Irradiate us, and we become involved.

Consider the Kargil war: Pakistan and India are not far from China, and the prevailing winds would likely carry radioactive fallout from an exchange into China.

I have no direct knowledge of this, but strongly suspect that China communicated its concerns to Pakistan and India... in no uncertain terms. Most likely, the US did the same, and quite probably the Soviet Union as well. So, even if Pakistan did consider launching nuclear weapons, the threat of intervention from the three major powers probably quelled that discussion very quickly.

Answer 8

Do political scientists and experts agree

The "political experts" exist all around the world. Their views and public comments are highly influenced by domestic political agenda. You don't really expect they could ever agree on something important. And I'm 100% sure I read a ton of contradictory opinions on this matter. But if you're particularly interested in what Russian experts normally say about a possibility of Russia's "first nuclear strike" under any imaginary circumstance, your quote is rather representative: no and never. Whether this should be taken seriously or not is another question.

which possess strategic nuclear weapons and a second-strike capability, the fighting sides will refrain from using nuclear weapons of mass destruction no matter what, just as Nazi Germany refrained from using chemical weapons in WWII?

Such "second-strike" must be highly effective to have any significance. For example, Japan had and had used chemical weapons against China during WW2, but then the USA still made two nuclear strikes against Japan, as they had no ability to respond.

So, if some day the USA will be able to build an adequately effective counter-ICBM system, then a nuclear strike against Russia will become quite possible.

Therefore, the problem of the deterrence is the problem of numbers only.

What if the losing side starts using its nuclear weapons of mass destruction in a limited way (i.e., tactical use against the enemy's military forces and/or limited strikes to the enemy's territory and civil population)?

"Limited strike against enemy's territory with the use of strategical nuclear weapon", assuming that the enemy has such kind of weapon too, is simply an oxymoron. If the USA sent only two "little boys" onto Moscow and Saint-Petersburg in 2019 they get 1000+ guests back immediately. That's simply out of question.

And if we speak of tactical nuclear weapon only, it has no such significance. Currently even Russia and USA have less than 1000 "tactical shots" each. That's maybe a dozen of strategical missiles in total or less than a year of intensive big "conventional" war. So it would have been used only as a supplement to strategical weapon. Otherwise, it does not worth it.

From what is written above, it implies that we precisely know there exists a single country in the world which is morally ready to employ nuclear weapon under any favorable circumstances (the USA); the other one we don't know exactly (Russia); and a few others that surely won't, because they don't have enough firepower yet (e.g. if tomorrow DPRK will be invaded by USA/South Korea, they will fight back using only conventional weapon, no matter what experts/tv/propaganda say).

Answer 9

The nuclear arsenals of Pakistan and India continue to grow, and they have had conventional wars in the past.

Pakistan has declared that it would only use nuclear weapons if it could not stop an invasion by conventional means or if it were attacked by nuclear weapons. Unfortunately, the two countries have had four conventional wars (1947, 1965, 1971, and 1999) and many skirmishes with substantial loss of life since the partition of British India in 1947. Therefore, the possibility of conventional war becoming nuclear is of concern.

Via: Rapidly expanding nuclear arsenals in Pakistan and India portend regional and global catastrophe

A conventional war in 1999 between the two countries had serious potential to escalate to a nuclear exchange. The US government advised personnel at the time to prepare to leave India to protect themselves. There is reporting that the CIA anticipated that Pakistan was preparing to use nuclear weapons against India at that time.

Mr Riedel wrote: “The morning of the Fourth, the CIA wrote in its top-secret Daily Brief that Pakistan was preparing its nuclear weapons for deployment and possible use. The intelligence was very compelling. The mood in the Oval Office was grim.

Pakistan's nuclear doctrine declares that it will use its arsenal if invaded or attacked, even by conventional means.

Answer 10

As far as I know, even though neither India or Pakistan used nukes during the Kargil War, Pakistan reportedly was seriously considering it. [1][2] So the answer to the question is it depends on the people running country being attacked and what the (I am using the term loosely here) "business case." Some people have no qualms killing themselves if that means they can take many of their perceived enemies together, like Samson [3] did. On the other hand, if your enemies believe you would unleash your nuclear weapons if they crossed a certain line, they may be careful not to cross said line: the principle of deterrence and basis of the Mutually Assured Destruction policy.

[1] https://yaleglobal.yale.edu/content/day-nuclear-conflict-was-averted

[2] https://www.independent.co.uk/news/world/asia/pakistan-india-nuclear-bomb-kargil-war-former-cia-officer-sandy-berger-bruce-riedel-a6758501.html

[3] https://en.wikipedia.org/wiki/Samson#Death

Answer 11

Do political scientists and experts agree that ... fighting sides will refrain from using nuclear weapons of mass destruction?

Those who are well-acquainted with the strategies and values of the potentially warring parties would be the most qualified to answer. All other answers will be ignorant of the facts. You could read some books such as this one on Soviet military strategy to get an insider's view of their strategy as of about 50 years ago (Soviet military strategy has not transformed fundamentally in a century; numerous accounts confirm this):

Deception and surprise in the Soviets view played critical roles in both the air and ground phases of the war. This judgment reinforced the existing Soviet belief that recent technological developments have placed an even greater premium on the conduct of deception and the achievement of surprise. Both are absolute necessities if a state is to achieve success in future warfare. Soviet Military Strategy in the 1990s: Alternative Futures By David M. Glantz

At last count, the Soviets had over 12,000 nuclear warheads. We stopped counting nearly 30 years ago.

Any experts who are susceptible to their influence will likely be persuaded to misrepresent the true case, or will be so beguiled that they are not even aware of what is true. Yuri Bezmenov, a defector from the Soviet KGB, alerted us to this practice nearly 50 years ago.

I will not be surprised when they use their nuclear weapons, even without apparent provocation.

Anyone who says differently is ignoring the key elements of Soviet war strategy: Deception and surprise.

One interesting footnote to which I am an eyewitness: Despite its supposed collapse as the headquarters of the USSR in the early 1990s, Russia has retained a tight grip on its nuclear and ballistic missile capabilities and space program--so much so that the United States has been buying many of its rocket engines from Russia for decades, for millions of dollars a piece, as Russia has continued manufacturing them. As detailed in this report, the loss of their business over the Ukraine war leaves a significant gap in our rocketry programs that we have no ready solutions to, and likely poses an actual, non-negligible national security risk. How did the United States become dependent on its Cold War adversary to supply key rocketry components?

Logistically speaking, a MIRV (Multiple Independently targetable Re-entry Vehicle) is much more difficult to intercept than a single warhead, and somehow the US has been beguiled into making all of its ICBMs single-payload, while Russia recently completed upgrading all of its ICBMs to have multiple MIRV warheads per missile.

There are many more instances of defense priority inversions, I am only scratching the surface with these examples.