No, most countries are not like Iran. There are enough examples of governments deciding to slaughter unarmed people within their boarders that the majority in the US sees giving up private guns as a folly of the greatest order.

If a populace gives up their weapons they become ultimately powerless against armed aggressors. 2A first purpose is to make citizens the first line of defense against invasion. This is supposed to be in place of a standing army from a time that a town could be wiped off the map by invading forces before any military force could be dispatched.

Yes, a permanent standing army is unconstitutional (Article 1 Section 8).

You might want to read up on French history if you think they are not capable of bloodshed.

The problem is that the people with guns also happen to be, by and large, the people who very much support what ICE is doing. Whereas those who oppose it have enthusiastically disarmed themselves.