2. He did it illegally while not having the power. That was my point!
You didn't say anything about "illegally." Anyway, the US supreme court appears to disagree with you on that point, at least to the point where they don't care to rule on it, and they're the ones whose opinion matters.
The last Congress shamefully ceded its power to him.
Minus the "last" part, yes, that's my point, which I stated explicitly in my original post that you decided to disagree with:
US governments, particularly the post-WWII ones, have consistently passed laws giving the president more and more emergency powers which, combined with a little creative wording, has given them more and more power generally. The US has changed from having a government dominated by an elected assembly with a subordinate executive to one dominated by one person with very broad power. Russia uses euphemisms for war for propaganda purposes. The US uses them to get around awkward bits in its constitution.
In order to make things like the war in Iran illegal the US congress needs to pass laws, which are subject to veto. Both to head off the interpretive power creep a la the Iran war and to repeal previous legislation that did that ceding you mentioned, like
- the War Powers Act: "do WTF you want for 60 days... lol, we had a cease fire so now it's a new 60 days!"
- the very open ended 2001 Authorization for the Use of Military Force: "Say the magic terrorist word. Okay, military force authorized!"
The 2001 AUMF is what Trump is using to justify blowing up boats in the Caribbean, BTW. Thus "narco-terrorists."