How is judicial independence ensured for International Tribunals?

Question

According to this article, Mladic's conviction by International Criminal Tribunal for the former Yugoslavia (ICTY) in The Hague found widespread international support. However, this opinion is not shared by all leaders (my emphasis):

However, the Serb member of the Presidency of Bosnia and Herzegovina, Mladen Ivanic, said the court had not shared justice among Serbs, Croats and Bosniaks.

"The Hague Tribunal has brought distrust instead of trust, and instead of reconciliation, it will lead to new political conflicts. The verdict of General Mladic shows that they continue with a negative attitude towards the Serbs and that the Hague Tribunal will remain remembered for not sharing justice but politics," Ivanic said.

Ivanic accused political interference in this case. This made me wonder about how judicial independence is ensured in such cases.

According to Wikipedia, "Judicial Independence is vital and important to the idea of separation of powers". However, separation of powers seems to be a concept at the state level, not international level:

The separation of powers, often imprecisely and metonymically used interchangeably with the trias politica principle, is a model for the governance of a state.

Question: How is judicial independence ensured for International Tribunals? Theoretically, they operate at an international level and classic separation of powers (state level) does not directly apply to them.

Answer 1

How is judicial independence ensured for International Tribunals?

When an international tribunal is formed, the treaty that gives rise to it (for that is the only way an international tribunal can come into being) sets forth how the tribunal will operate and select its judges. This treaty and the goodwill of the countries entering into it, is the sole way that judicial independence is ensured.

Their functional independence is usually something that simple arises structurally, because the tribunal is not subordinate to any other government or official except as set forth in the treaty establishing it, rather than something that has to be formally considered and protected.

Sometimes, as a practical matter, sheer neutrality and independence isn't even desired.

For example, in the Nurenberg trials, there was no pretense of attempting to establish a system in which the tribunal was balanced between pro-Nazi and anti-Nazi elements. The judges were selected by the powers that convened these tribunals in order to carry out an agenda of punishing particular people on the losing side of the World War II whose acts were deemed by the winners of that war to be particular deplorable. In some sense, that is the opposite of independent at the big picture level, even if the convening powers didn't intervene in the minutiae of each trial because they trusted the judges that they appointed to run that trial to be faithful to their objectives.

It is more fruitful to think about international tribunals as forums in which treaty created or treaty recognized rights can be enforced, than forums in which disputes can be resolved impartially.

The creators of the tribunal want to prevent it from punishing people that they didn't intend to punish, but don't really care if the people punished or their allies don't agree that it is fair to punish them for the offenses the tribunal is authorize to punish.

Since the laws or standards that an international tribunal enforces have a non-neutral agenda in most cases, to that extent, these tribunals are inherently not full impartial themselves.