Why is sending troops different from sending military equipment?

Question

In the current war with Ukraine it seems like the West can send any forms of weapons (short of nuclear warheads) to Ukraine without causing the conflict to escalate beyond Ukraine’s borders. This includes long range weaponry capable of hitting military targets within Russia’s territory. However it seems like sending actual troops is out of the question as this would cause a significant escalation of the conflict.

Why is this the case? What’s the difference between sending a HIMARS launcher and sending a battalion of troops?

Answer 1

Already many good answers, I just wanted to add another facet

The weapons change ownership; the soldiers don't.

If Poland (for example) sends a gun, a tank, an airplane to Ukraine, the moment the Ukrainian army takes control of them; those are part of the Ukrainian army. Whatever they are used for, they are used by the Ukrainian army. If they kill Russian soldiers, those soldiers have been killed by the Ukrainian.

But troops would remain part of their original army. Anything they do against the Russians, they would do as part of the Polish Army, guided by Polish officers, following the orders of the Polish government to which they still owe allegiance. It is a far more direct foreign implication.

The reverse also works: if the Russians destroy a tank provided by the Polish, they still have attacked just an Ukrainian tank and not a Polish one. But if they bomb a Polish company, the casualties would be Polish soldiers, not Ukrainian.

So, while the intent of both sending materiel and troops is the same and the effects may be sometimes similar, it changes the nature of the conflict as it means direct combat between the countries giving support and Russia.

Answer 2

"Escalation" is mostly a red herring.

The big difference between sending weapons and sending troops to an ongoing war is that a dead soldier has a much larger political cost than a destroyed rocket launcher. Simple as that.

The same works in reverse. Having your troops killed by american soldiers is (politically) something else than having your troops killed by american weapons.

Answer 3

International law is mostly based on precedent.

• There is the precedent that selling arms is not, by itself, an act of war. This was e.g. supported by cash and carry during the early phases of World War II, when the US was not yet a belligerent. There were other, earlier precedents that neutrals may not sell arms in the Alabama Claims, so it is not completely clear cut, but recent precedent seems to indicate that selling arms to a belligerent is not an act of aggression. (It will be seen as unfriendly.)
• There is a precedent that sending troops which do fight under the flag of the sending country is an act of war. It is a bit less clear how to treat large numbers of volunteers.

Regardless of law, there is something of an understanding that one does not push a nuclear power beyond their reasonable red lines. Those red lines are not necessarily based in international law, they are based in power politics. When the Soviet Union deployed nukes to Cuba, that almost triggered WWIII. Not because basing nuclear missiles in Cuba is fundamentally different from basing nuclear missiles in Turkey or the UK, but because it represented a change in the political balance that was unacceptable to the US.

The obvious problem with this realpolitik view is that it may allow nuclear powers to "get away with" unjustified actions, simply because nobody is willing to start a world war over them (compare the stability-instability paradox).

Where exactly these red lines are is a political bargain, with the mutual understanding driven in part by the diplomatic declarations of both sides.

• Russia is trying to establish that any strike on Russia (including annexed territories) and any delivery of weapons capable of deep strikes is crossing a red line. Those are two different issues, by the way.
• The West is not accepting the full claim of the Russian red line, but it has been reluctant to deliver such things as Western-made tanks and IFVs, long-range missiles, or combat aircraft. It has been delivering Soviet-made tanks and Western-made rocket and tube artillery.

The West wants Putin to be defeated, but it does not want him to panic. Those two goals may be mutually incompatible, so what the West does may be characterized as not letting Putin win, which is slightly different from him being defeated.

Answer 4

Help of the western countries to Ukraine seems moderated by multiple barriers. HIMARS reaching 92 km are okay but ATACAMS reaching 300 km are not. Old tanks of 1970 year design are okay but the modern Leopard 2 are not. Drones are okay but military aircraft are not. Striking Russian munition depot in Ukraine with American rockets is okay, striking the same depot in Russian territory across the border is not. Lots of various economic sanctions are okay but using up the seized bank assets belonging to Russia state is not. Calling Vladimir Putin a war criminal that "should not remain in power" is okay, but naming Russia a terrorist state would be too insulting.

It is not clear how are these barriers established but the goal is probably to moderate the actual escalation of the conflict. They indeed look like some "hidden contracts": even if Russia declares they do not tolerate any intervention at all, they actually accept some within these limits. Sending troops currently belongs to barriers EU and USA opt not to cross.

Answer 5

When soldiers of country X are tasked * with killing soldiers of country Y, there is one generally accepted word for it: War, between X and Y.

In contrast, when country X "only" supports forces engaged in a war with country Y, country X is not considered at war with Y.

Let's take some examples:

Vietnam

Russian and China support North Vietnam, fighting the USA. At war: North Vietnam vs USA + South Vietnam.

Afghanistan 80s

The USA + Pakistan support the Afghan rebellion against the USSR. At war: USSR vs Afghanistan rebels

South Korea, first phase.

Russia and China support North Korea vs South Korea and USA. At war: N Korea vs S Korea + USA.

South Korea, second phase.

China intervenes in North Korea vs South Korea and USA. The "war" state vs China is problematic and intentionally kept limited by the US, but Mac Arthur does not see it that way and loses his job for it.

Note that 1950s China is not nuclear which probably contributed to Mac Arthur's rather cavalier attitude.

At war: N Korea and arguably China vs. S Korea + USA.

Bottom line: there is a huge difference, historically, and that includes Cold War conflicts involving both Russia and the USA, between being an active belligerent and providing support. Both NATO and the Warsaw Pact took great care not to put their troops into direct conflict, even though both at times provided ample material support against the other.

Let's keep it that way.

* as opposed to cases where either there are accidental deaths or there is a localized, unplanned, incident leading to deaths.

Answer 6

World Politics is complicated, but in the end there is no final law or arbiter. It's just what the head of state decides and maybe what the population thinks of it. Whether something is considered "fair" or "right" is shaped by the laws we live by in our personal lives.

Compare it to existing, accepted laws in most countries around the world, certainly Russia, Ukraine and any arms supplier, lets say the US, UK or Germany:

If a man gives you 100$ and in exchange you give him a knife, when they subsequently murder their wife with it, that is not the fault of the seller of the knife.

If a man gives you 100$ and in exchange you murder their wife, that is called being a contract killer, and it's illegal, as is hiring a contract killer in the first place.

So to summarize, selling goods means you are not responsible what happens with the goods afterwards. Selling services? You are responsible for that service. You cannot just claim that you only did that because you were paid for it. That does not absolve you of any crimes.

War is nothing but murder at scale. Supplying the weapons still means the other guy (or country or nation) is responsible. Supplying the actual service of killing enemies? You are in on it.

As a comparison, when the headlines broke that Russia bought ammunition from North Korea, nobody suggested that North Korea would become a party in the war. Not any more than if they had sold toilet paper or socks.

Answer 7

Sending weapons and equipment is at heart a political/economic transaction. Nations send weapons to each other regularly, whether or not there is a current conflict. Sometimes armaments are bought by a state trying to shore up its military; other times they are offered to satisfy the security interests of the providing state. These kinds of deals can be controversial politically, but they are usually regarded as normal international transactions.

By contrast, sending in troops (aside from 'military aides') or firing long-range weaponry into combat areas usually signals that a nation is involving itself in a conflict directly, either as an act of war or as an emergency interdiction. The nation then becomes a combatant, and as such its troops, ships, bases, supply lines, and military production facilities become valid military targets. That creates the opportunity for major escalation.

Not to put too fine a point on it, but so long as Americans and Europeans don't shoot at Russian targets directly, Russians are constrained not to shoot directly at American and European targets. We can supply the Ukrainians with materials to fight their own war against Russia, but taking part in that war would open the door to Russian retaliation.

Answer 8

Many good answers are here, indeed. However, I believe that two key factors are not covered yet:

What’s the difference between sending a HIMARS launcher and sending a battalion of troops?

A battalion of troops implies a battalion of their spouses, 2 battalions of their kids, and 2-4 battalions of their elderly parents.

Even though these brave people may have volunteered to go risk their lives (contrary to just receiving the order), supporting their families would be a responsibility of their governments in case if anything happens with their lives or health. This always seems a hard decision for any government that cares of their people.
Human's life is the ultimate goal in the Western world.

Also, if losses actually occur, russian agents could try inflating social unrest in Western countries that even could overthrow the government. Just like they did it before:

Russian GRU defector Stanislav Lunev said in his autobiography that "the GRU and the KGB helped to fund just about every antiwar movement and organization in America and abroad," and that during the Vietnam War the USSR gave $1 billion to American anti-war movements, more than it gave to the VietCong, although he does not identify any organisation by name. Lunev described this as a "hugely successful campaign and well worth the cost". — Wikipedia

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Ukraine has enough motivated people. Ukraine needs weaponry.

Unlike pictures you might have seen today on Russia (young people trying to evade mobilization), Ukraine has sufficient number of motivated young men and women who are ready to fight and who voluntarily go to the Armed Forces.

Here are queues at Military Commissariats in Rivne city on the first days of the full-scale invasion, circa 28/Feb/2022 (source)

Many Ukrainian politicians also stress that Ukraine needs weapons:

Poroshenko: 'For peace we need three things: weapons, weapons, weapons' — Deutsche Welle

Answer 9

Military equipment is property whilst military personnel are men. There is a fundamental distinction. It's the same difference in criminal law that distinguishes damage to property from murder.

Sending military equipment is a way of showing support without escalating the conflict more widely.

Answer 10

I think it's a question of "leaving options on the table". It's a way the west can tell Russia "we'll tolerate your war of aggression against Ukraine but think carefully about how you conduct it because we have a lot more cards we could play".

Russia could deploy chemical, biological or nuclear weapons. I think they could have done more to attack Ukrainian ability to ship out grain, or start really going after civilian sea traffic in the Black Sea. So I think there's an argument that while the West isn't "all in" on this war, neither is Russia. And the West can possibly prevent Russia from going "all in" by the very fact that we aren't all in. "You don't cross that line and we won't cross this line" says each side to the other side.

I also think there's a strong argument to be made that really the war is not costing the West much, so the way we are conducting it now is practically free. You'll hear about the billions it's costing but the bottom line is we are mostly sending weapons we would never have used, and would have replaced within the stockpile over time anyway, so the cost of throwing an old Javelin into the dumpster is probably higher than the cost of handing it to the Ukrainians to go shoot it at some Russians instead. It comes out of the balance sheet as "cost of war" but I think you'd find "cost of not doing anything" would have been very similar. We aren't producing F-22s to give to Ukraine. The west is mostly giving them weapon systems that would otherwise just be collecting dust so the cost is a bit of a wash.

If the west sends troops, though, they will also send the latest and greatest top end equipment, and any losses then will be very real losses, both in lives and in brand new equipment that must be replaced.

The moment we send troops -- even, I think, a "no fly zone" -- is the moment a lot more cards go on the table and the closer both sides move to all out war.

Answer 11

Letting Russia taste its own medicine

When the Russian army invaded Crimea and Donbass, RU government denied any involvement:

• "Их там нет" (they aren't there) - the famous phrase of Vladimir Putin when asked about the Russian soldiers' presence.
• "Форму можно купить в любом магазине" (anyone can buy Russian uniform) - from the same speech. The claim was that the Russian-speaking local people self-organized, captured arms from the Ukrainian army and rebelled against the Ukrainian government.

Later, Russia half-heartedly admitted helping the "rebels".

Even later, this claim was silently, but completely dropped as proofs about the opposite fact piled up.

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An important point in the Russian propaganda is that Russia fights NATO and Ukraine is only a tiny facade. The propaganda pictures countless NATO instructors, officers and even ordinary soldiers in Ukraine. This point has its supporters and beleivers in Russia, in Ukraine and even in NATO countries.

Another important point in the same narrative is that the "West" holds Ukraine hostage and Ukraine soldiers are fighting against their own will. This is the whole idea of "liberating" Ukraine.

On the other hand, not fueling Russian propaganda is considered important by everyone (except, of course, Russians).

In a sense, the "red lines" that the western partners of Ukraine are reluctant to cross, are based on the perceptions of the general Russian population.

The propaganda is not omnipotent - even in Russia.

This precludes sending any military personnel in Ukraine (if there is at all a compelling reason to do so).

Answer 12

The first thing to note is that your premise is not entirely correct: The West cannot send (i.e., sell) "any forms of weapons (short of nuclear warheads) to Ukraine without causing the conflict to escalate beyond Ukraine’s border":

Russia has made clear that sending long range (even non-nuclear) weapons would make the sending country a war participant, presumably because those weapons would facilitate attacks on Russian territory that would otherwise have been impossible.

In short, everything that would presumably be traded in normal times does not in itself escalate the conflict. That is probably one of the reasons that there is a certain reluctance to send Western war tanks and other weapons systems that would imply that Ukraine is becoming integrated in the Western military infrastructure.

Russia has also made remarks that could be seen as hedging the option to e.g. bombard supply lines outside Ukraine if the weapons deliveries take on a quality that makes the seller seem like an active participant. Similar limits have been alluded to regarding reconnaissance and weapons training, especially training in Ukraine, even if the instructors do not participate in fights.

The second reason is that if we considered all countries who sold weapons used in conflicts parties to the respective conflicts, all major military powers would be or would have been parties to most modern conflicts on Earth, because selling weapons is such a profitable business that no major military power refrains from it, including Russia itself which is only surpassed in death dealings by the U.S. Making the countries who facilitate wars by providing the weapons party to the conflict would eliminate this opportunity for obscene profits, so nobody in their right mind would propose that.

The reason, on the other hand, that sending soldiers makes a country a party to a conflict is self-evident: Because the country now is a party to the conflict.

Answer 13

What’s the difference between sending a HIMARS launcher and sending a battalion of troops?

Just because nobody said it in other answers let's first say what it's not a difference in. It's not a difference in that it both would increase the military strength of the Ukrainian side resulting in higher loses on the Russian side. This battalion surely will not come unarmed and weapons will surely not be sent to civilians. So in any case arms and military personnel together result in an increased military force.

The main difference is what Guran states, involvement of people is raising much more emotional stakes than involvement of artificial devices even though from a factual perspective it hardly matters how exactly increased deadly force is achieved when it shows its impact. That's why one of these is typically considered war and the other one rather not.

By the way: the question of who is at war with whom or not is not so interesting either. Officially Russia isn't at war either. The more important question is what actions risk extending the scope of the combat zones. That's probably what actors are considering here. And if you commit servicemen, you cannot easily go back. For example, can you imagine Russia seeing the errors of their ways and retreat tomorrow? Neither can I.

Answer 14

At the moment the West is deniing russian claims about war between Russia and NATO. Sending troops would be exactly this kind of war, also called World War 3. Such war would be very likely a nuclear one. Hope I was able to explain in brief the diference between a proxy war, we know from the time of the Cold War and World War 3.

Examples for proxy wars, mentioned befor are Vietnam and Afganistan. This countries were suplied with weapons by one of the opposing sides of Cold War to fight the other one.