What do you think Reagan would have said to these jokers in the UN in these past meetings.?

To Poland: "I look forward to maintaining this friendship we have had since Lech Walesa. You can of course depend on the United States to defend you against any threat."

To Russia: "Until you prove otherwise you ARE that 'any threat.'"

To Venezuela: "Since we will be allowing the oil companies to build new refineries and pursue oil and shale oil exploration both offshore, in Alaska and in the northern midwest, we have no need for either your oil, or your venomous leader, or your business. We are placing an embargo on ALL Venezuelan products and services, and we are increasing our military support of the governments in Columbia and Brazil."

To Libya: Khadaffy is too silly for Reagan to even bother mentioning. Though all he would have to say is "1986" to have Khadaffy lose control of his bodily functions.

To Israel: "We will support ANY choice you make in dealing with the Iranians or the Palestinians. It's your land. Defend it."

To Iran: What Iran?

Those on the Left will make lame jokes about this answer, while we on the Right will either say "We don't know", or remind you that Reagan, a great President, is dead, which makes your question meaningless.

One thing I feel reasonably sure of, is that Reagan would not be bowing to foreign royalty, or be in any way chummy with terrorist and quasi-terrorist, heads of state. He may have been many things, but @sskisser certainly wasn't one of them.

Above all, we must realize that no arsenal, or no weapon in the arsenals of the world, is so formidable as the will and moral courage of free men and women. It is a weapon our adversaries in today's world do not have.

Ronald Reagan

Were you listening? Reagan's words were read as part of the dialog.

"In our obsession with antagonisms of the moment, we often forget how much unites all the members of humanity. Perhaps we need some outside, universal threat to make us recognize this common bond. I occasionally think how quickly our differences worldwide would vanish if we were facing an alien threat from outside this world"

Maybe he would have to ask his monkey chimp pal Bonzo from his movie "Bedtime for Bonzo" what to say. That idiot never had anything in his empty head. No wonder he quit acting and got into politics.

P.D.: That's funny, I thought Reagan was the one who should have been sent to kindergarten. HA HA HA! And LOVE those five demerits. Bashing Bonzo's pal Reagan is my kind of sport.

Nothing. He's dead.

EDIT:

or he'd give a speech akin to the "Tear down this wall" speech, and like that one was, it would be deified in the US but largely ignored in the rest of the world, and would have no actual impact on anything.

or maybe he'd refute Obama's calling out of Israel's breaking of the armistice lines, saying that Israel can break any treaties it wants because they're special and above the law, further antagonizing Iran, leading to the development of Iran's first nuclear strike, leading to WW3 and its inevitable nuclear apocalypse. (this one's admittedly a little reductio ad absurdum, but the fact that OP is probably referring at least in part to Obama's reference to Israel's super illegal settlements in Palestine, which would normally be considered an act of war, is still relevant).

My main man Reagan would have stood up, looked that azzwipe straight in the fact and told him how it is. Reagan wouldn't mix words, he would come right and and say " YOU ARE A LIAR, EITHER STOP AND STOP NOW OR YOU WILL BE WIPED OFF THE FACE OF THE MAP."

In that very charming manner of his, he'd have told them to "drop dead".

"the bombing will commence in 5 minutes"