"We have just released a public opinions survey...which demonstrates that the American public is four-square behind supporting Ukraine militarily," says Ivo Daalder.
"It's better to think about this as just a catalyst. If there were no exercise ongoing, then of course North Korea would find other reasons to launch missiles."
Carnegie nuclear policy senior fellow Ankit Panda discusses recent nuclear saber-rattling by Russia and North Korea and whether the risk of nuclear conflict is growing.