> They have anti air weapons in embassies and wait for a military helicopter transporting a high value target?

I agree with you that it seems relatively unlikely that there would be a large weapons cache inside an embassy. I want you to consider the opposite scenario of what you're dismissing though.

If an American CIA officer in Russia wanted to shoot down a helicoper, do you think it would be that difficult for them to get ahold of a rocket launcher and do so?