>> They're gone. And Hillary, I just->> Strangely overlooked in Monday's fiery debate, but still reverberating in Washington two days later, Donald Trump's musings about when to unleash a doomsday nuclear assault.>> Once the nuclear alternative happens, it's over.>> Trump asked to weigh in on whether the US should give up the long-standing option of a preemptive nuclear strike.
>> President Obama reportedly considered changing the nation's long-standing policy on first use. Do you support the current policy?>> I would certainly not do first strike. At the same time, we have to be prepared. I can't take anything off the table.>> Trump apparently unaware that he was taking both sides in the argument, rejecting a first strike, and then leaving the option open.
>> Foreign policy reporter, Jonathan Landay.>> Those are conflicting positions, and seem to indicate somewhat of an incoherent position that Mr. Trump has on this very important issue. The proposal before Obama would have the United States pledge that it would not be the first country to use nuclear weapons.
But we just don't know from what Mr. Trump had to say, what his position is.>> Landay says it's far from a hypothetical question.>> The so called US nuclear umbrella is a means by which the United States has helped try and limit the spread of nuclear weapons.
That policy has the United States providing nuclear weapons coverage to many of its allies. Therefore, the thinking being that they won't need to develop their own arsenals. This is particularly true in the case of Japan and South Korea, which are believed to have the ability to produce nuclear weapons, but haven't.
The fact is that they are threatened by a nuclearized North Korea and they need the assurance of the American President that they will in fact be able to count on him using nuclear weapons in the case of a war.>> China should solve that problem for us.>> Trump rattling more nerves on Monday when he suggested China should quote, go into North Korea to remove the threat.
Trump's seemingly cavalier attitude towards nuclear policy has been an ongoing worry. Earlier in the campaign, saying South Korea and Japan should get their own nuclear weapons.