Does Iron Man have authority to arrest anybody( even Dr Doom)?

I Don't Know
This Is An Interesting Question

 

Depends if Latveria is part of the UN or not or whether he has commited some sufficient war crimes

i imagine it being a little bit like saddam with them being able to perhaps arrest and detain him if they believe he is a threat to the united states and his own government but ultimately he will have to be released into the custody of his own government where he will be put on trial and ultimately get off.

I am also unsure how much his diplomatic immunity will get him in the long run...

 

depends on if SHIELD is UN sanctioned or part of the American Military.

 

The SHIELD is under UN authority, but it has heavy American influence because the United States pays for most of SHIELDs budget. Probably explains why every Director of SHIELD is an American and often sides with the United States in conflicts (Civil War, possible war with Atlantis, and World War Hulk).

 

there was a while back that Marvel forgot that and had it a part of the American military

 

Marvel should change this up I bit I think. Maybe a Brit could run it? Or someone from Wakanda

 

I don't. I feel it makes the Marvel Universe seem more realistic. The United States pays for the vast majority of SHIELD's budget. It makes more sense for the organization to basically kowtow to the United States as a result to keep getting the funding and more.

If someone with a different nationality, particularly someone like a Wakandan (which the United States currently has testy relations with) ended up in charge, such funding would probably decrease.

 

Another question stemming from that would be I think how much Diplomatic Immunity des someone like Dr Doom have? I think in order to actually arrest him under the "crimes against humanity" he would need an international backing not just a District court (or other american judicial warrant)...

 

Whether part of you UN or not, the answer is no. The UN does not have the power to arrest anyone either. Now if a tribunal conducts a war crimes trial and doom is convicted then yes, but even that is just reasoning and a group imposing rules upon an individual. No country has the "legal" ability to arrest any foreign leader regardless of anything. One nation does not have authority over another, you can force a nation to do something, but even if every nation in the world agreed against one single nation (which will never happen) it's still just popular opinion. The only case this would not apply to is if a nation agreed to a treaty, compact or such and broke the terms of it, but I highly doubt Doom's signed on to the Geneva Convention or any other compact.

 

Though the US could consider the symbiont(if you read DP you'd know that's the correct way to say it.) bomb an act of war and invade his country. Though it would have taken a hell of a lot more time to get permission to do that then to just bust into his castle bust s**t up. One of the perks of being a private citizen in tights I guess. You don't need permission to invade a country. You just do it, and damn the consequences. If Bendis is smart, Stark'll have hell to pay for this after all is said and done.