UN govt officials who sanction drone strikes can not be tried for war crimes because they're diplomats of a sovereign organisation. You have to understand what kinds of people these are (in general). They're part of powerful political families, spoiled rich kids with entitlement issues that would make all US congresscritters volunteer for public apologies. They don't agree on anything, least of all human rights (note that the UN human rights council is dominated by governments that don't respect human rights. Which is why the only government to get dinged on human rights is the one government that actually attempts to respect human rights in the region). They will go to war if they saw any of their members threatened with so much as a citation. So no they can not be tried for war crimes.

They will, however, attack others every now and then.

So international law, and human rights, effectively don't exist. So of course since this is just used as a political tool, it can be cheated with when convenient. That's why they went so ridiculously hard after Serbia and let (for example) North Sudan/Egypt/Saudi Arabia/... continue their crimes without a peep.

Even when they do have money, it only works when enforcement works. So in order to get a conviction you need :
1) the political interests need to be aligned
2) some military needs to kidnap the sacrimonial lamb* and this can't lead to an incident
3) the lamb can't have any good political structure left to support him

That's all international law is. Look at the money behind it and you will understand how it works. Attempt to analyse it legally and it will remain a mystery. Look at the conflict between Russia and Saudi Arabia and you will see why they intervened 10 years after the Yuguslav wars, and why they only convicted Serbians, and take note that in this "genocide" of civilians, first only young males, armed, were killed. The whole thing was precipated by an attack by said "victims", which was obviously part by an attempt at territorial conquest by said victims, and more than a few of the perpetrators died. Another army tried to intervene and couldn't because it suddenly found itself under attack by the "victims" and the commander decided to withdraw (it's not that they couldn't intervene, they didn't after finding themselves under attack by the victims). Both America and Europe took the side of the "victims". Understand why that last part happened, who was on whose side, and you'll see where the convictions come from, and just who and what the ICJ is working for.

Note that I'm not making the case that all governments are corrupt (beyond a certain degree). Just that a toothless, powerless, jurisdiction-less, "court" 100% dependant upon foreign interests cannot have a shred of integrity in practice.

But of course, don't let reality stop you from feeling entitled, and in the US, and some parts of Europe, you can actually more-or-less enjoy these rights (keep in mind that in the EU, due to WWII, you don't have full freedom of political opinion. If you think human rights will save you from conviction if you do something that's technically a human right but flies in the face of this policy, don't expect human rights arguments to save you from conviction. In Europe freedom of ideology does not apply nazism and a few forms of communism/socialism). If you actually wish to test human rights policies though ... I'd advise you NOT to leave the US.

* they're generally guilty, although proof tends to be lacking in the extreme, and people convicted are generally not the only guilty parties.