For the War Crime Court to work as a deterrence, two things must happen and both of those things must work empirically well. They are:
Imposition of specific punishment on offenders so that they don't commit further crimes (Eg: Charles Taylor)
Making punishments severe so to create fear in others from committing similar crimes. (No Example or evidence available anywhere.)
Both principles have to work equally in order for deterrence to be effective.
But they don't at least there's no evidence of the second (#2) supporting principle above.
Here are the problems with relying on WCC for deterrence:
WCC wrongly assumes that the former warlords will become future warlords if they are NOT isolated. (Eg: This is erroneous because Taylor wouldn't become a warlord again even if he wasn't in prison).
WCC also wrongly assumes that the fear of severe punishment will prevent any future war. This too is erroneous because since the ICC was founded in 2002, there has been 81ARMED CONFLICTS across the globe compared to 68 ARMED CONFLICTS prior to its establishment. You would think that the establishment of the court would have prevented these 81 additional wars since, in fact, it's about justice and deterrence.
There's no evidence, empirical or otherwise, to substantiate that if it weren't for the WCC a particular country would have gone to war with itself or to repeat a war with itself.
Now, from WCC not serving effective deterrence, let's discuss why the WCC is more about politics than it is about justice or victims of crimes:
If WCC was serving justice equally across the board and NOT about the will of the politically stronger nations, International Criminal Court would have prosecuted:
⇒American Servicemen for their roles in Iraq, Pakistan, and Afghanistan.
⇒Russian soldiers for their role in Chechnya or recently in 2014 for the death of thousands of Ukrainians
⇒Saudi Arabia's role in Yemen
⇒Isreal's role in Palestine
⇒Turkey's war with the Kurds and their PKK
⇒Iraqi officials, although Sadam was killed, his surviving officials should have prosecuted if the whole campaign was about justice and not just Sadam.
⇒Libyan officials, although Gadafi was killed, his surviving officials should have been prosecuted if the whole campaign was about justice and not just Gadafi
⇒Or at least the court would have prosecuted the current Ivorian President Alassane Ouattara for his rebel group's role against the then government of Laurent Gbagbo. But instead, the court supported the rebel leader (Ouattara) and prosecuted the country's former president (Gbagbo). What change the dynamics? France +a great power) supported one and not the other. You guess who...
THE BEST DETERRENCE is one that addresses the principal reasons for the issues so that the opposing sides do not fight in the future. If the roots of the issues are not addressed, you can grab a thousand persons and jail them, the problem will still continue.
ONE CLASSICAL FAILURE of using courts as deterrence was during the American Civil Rights Movement. If Courts could serve as a deterrence, then:
THE CIVIL RIGHTS MOVEMENT in the US wouldn't have succeeded. The Civil Rights movement saw the harshest of penalties in courts and at the hands of police, draconian laws, and the most inhumane treatments, yet people weren't deterred. Why? Because the conditions (such as segregation) that created the movement were still being practiced. So no matter how many people that were killed or jailed, as long as the root cause of the movement wasn't addressed, people continued fighting for their rights.
A CONTEMPORARY EXAMPLE of a failure of the courts as deterrence is the issue of massing killings (gun violence) in the US. You would think that the US has some of the best legal systems in the world, the biggest courts, and largest prisons, right? And so you would expect MAXIMUM DETERRENCE as a result, right? No!!! There are mass killings in places of worship and entertainment regularly. Have you wondered why people aren't deterred by the laws and the court? Well, its simple, there are still mass shootings in public places because the conditions (gun laws and white nationalism) that make these shooting possible continue to exist. THE CONDITION NOT THE PEOPLE. Putting one person in jail doesn't guarantee that another person won't commit the same crime!
The best deterrence is the one that: ⇒repairs the harm done to people and their community ⇒restores victims dignity ⇒holds offenders accountable ⇒addresses the root causes and all causal factors of the war ⇒does not create adversaries amongst ourselves ⇒furthers the country's transition
It is only Restorative Justice that adequately meets these effective deterrence standards, not WCC.