How do states trust each other to comply with treaties?

Question

There is no global power that enforces treaties so when entering into one a state has to make a prediction about whether the other parties will comply with it. I'm guessing they base their predictions on the reputation of the state. I'm also guessing that the prediction would be based on facts somehow; not just a general feeling of how trustworthy the others seem. What objective methods are available for a state to make this judgement? International rankings? Internal profiles of other states from intelligence agencies and such? In the case of loans, a state can go by the other state's credit rating according to Standard & Poor's, Fitch, or Moody's.

This question is of course only relevant for treaties where a state will be worse off if the other party doesn't comply, such as when making a loan to another state or when agreeing to demilitarize a border. If you don't face a risk when entering into the treaty you don't need to trust the other parties.

Answer 1

Generally, these problems are solved by applying game theory.

Basically, you evaluate:

• What is the rationality and payoff function for another state

  This can be non-trivial and nuanced based on who the actors are, e.g. the payoff function could very well be "this bad decision effs up the country by sets up a ruler with $1B in lifetime income"=>"maximum payoff from the view of said ruler". Or, "this decision ensures my re-election 3 years from now as it seems popular, despite the country facing major financial hit 10 years from now from consequences, when I won't care about re-election". ISIL/ISIS is an excellent example of this - their payoff functions include theological considerations that most Westerners just don't get.

  This gets even more complicated as "a state" isn't an atomic monolithic actor. There are various power factions (see "48 laws of Power") that may exert different vectors of pressure based on their own mini payoff functions.

  In theory, various negative consequences (international pressure, reputation loss, threat of kinetic action retaliation for violation of treaty, domestic pressure from power factions, domestic pressure from populace) feed into this payoff function. But as noted in previous paragraph, their weights may not always be the same. 85 year old family-less dictator may not really care about country's reputation loss. A guy with $9B in Swiss Bank Account may not necessarily worry about domestic unhappiness.

  • This calculation can be done both analytically (analyzing rulers) and interpolatively (what has the state done in the past? That can let you estimate payoff function in some cases).

• What is the optimal strategy for the other state based on said payoff function.

• What will the state likely do based on that optimal strategy.

Answer 2

Yes, it's based on reputation. They could consult a credit rating agency but generally those are only used by lenders looking to lend a government money, rather than nation states looking to do deals.

There are various international arbitration systems for resolving disputes, such as the WTO. While they ultimately can't force a country to comply with their decisions, the consequences for not doing so can be severe. Loss of valuable trade deals, credit rating damage, loss of property rights (e.g. the harmed party can ignore their patents and copyrights), that sort of thing.

Answer 3

Countries are pretty large organizations, however, governing principles of relationship between countries are similar to any other social group. How do you know that any of your agreements are going to be honored?

I will give few examples:

• How do you know your friends will show up to your birthday party? They did in the past 10 years, and you talk every week, and you didn't hurt them too badly recently. All these factors give you good chance they'll show up
• How do you know that when you bring lettuce to the check out, the price will be exactly as it was advertised in the veggie isle? Well, the store is pretty large, and you had good experience before. Also you know that if they try to defraud anyone, they might get backlash from social media. Plus, possible benefit the store can get from this fraud is minuscule compared to risk. Plus, you can always leave and go to any of many supermarkets around.
• How do you know the bank will not steal your money? There are laws and pretty stringent enforcing agencies, apart from everything else I said about grocery store.

Between countries, of course, relationships are harder. But I believe, you can use normal life analogies to understand some of the recent events.

Britain wants to get out of European Union (doesn't want to show up to party). That is because UK thinks EU stinks as a friend, for example, because they allegedly didn't listen to them for years.

Trump decided to engage in trade war and increase tariffs on good exchanged with China. Compare that to grocery store which decided to crank up price of potato overnight, because new management feels the price was unfair. It might work for store's benefit, but only if there is no other grocery store around, and market is cornered. In US-China situation, there is no another easily accessible market for both of them, so they have to lose money by either paying higher tariffs or establishing new ways of selling goods (trade with other countries).

Answer 4

In addition to the other answers here, it's also worth pointing out:

1. The International Court of Justice which provides for dispute resolution on international law. States can make "declarations" that they accept the courts jurisdiction. Although this is optional, it is a good sign of trustworthiness.
2. The Vienna Convention on the Law of Treaties provides for the "ground rules" on how treaties are to be interpreted (when they come into force, how they can be cancelled, etc.). This was intended to prevent a repeat of some of the misunderstandings of earlier treaties (e.g. UK / Spain disputes about Gibraltar arising from the Treaty of Utrecht)

Also, many of those countries with written constitutions have special provisions relating to treaties. For example, the United States has the Treaty Clause, which gives treaties the full force of US law, and takes them out of the direct political arena.

Ultimately, the extent to which any country will view a treaty as worthwhile will depend on the likelihood they see of the other country abiding by its provisions. Past history plays a huge role here.