Every president since Ronald Reagan has tried to reduce the world’s atomic stockpile, reports CBS News correspondent Margaret Brennan. President Obama signed a treaty with Russia in 2010 pledging those types of reductions. But on Thursday, President-elect Donald Trump appeared to upend decades of U.S. national security policy in a single tweet, writing: “The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes.”

The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes — Donald J. Trump (@realDonaldTrump) December 22, 2016

Mr. Trump’s transition team scrambled to clarify the president-elect’s tweet, which appeared to support the expansion of America’s nuclear arsenal.

“In his quest to keep us safe and secure, he’s putting the world on notice,” senior adviser Kellyanne Conway said on MSNBC.

“What he’s saying is we need to expand our nuclear capability, really our nuclear readiness or our capability to be ready for those who also have nuclear weapons. … I think that we’re getting a little too far ahead of ourselves that he’s changing policy and making policy in a way that he did not intend,” Conway also said.

Another Trump aide tried to clarify the comments Thursday, saying the president-elect was “referring to the threat of nuclear proliferation and the critical need to prevent it.”

Transition officials didn’t say what prompted the tweet, but it came after Vladimir Putin said Russia needs to “strengthen the military potential of strategic nuclear forces.”

Former U.S. ambassador to NATO Nick Burns warned the stakes are too high to risk a misunderstanding.



“In nuclear diplomacy and diplomacy in general, you want to be clear most of the time, especially with your adversaries, about what you’re willing to do and not willing to do,” Burns said.

But Mr. Trump’s comments on nuclear weapons during the campaign seemed, at times, to be intentionally vague.

“The United States has not used nuclear weapons since 1945. When should it?” CBS News political director and Face the Nation moderator John Dickerson asked Mr. Trump in January.

“Well, it is an absolute last stance. And, you know, I use the word unpredictable. You want to be unpredictable,” Mr. Trump said.

“Look, nuclear should be off the table… But would there be a time when it could be used, possibly, possibly?” Mr. Trump said on MSNBC in March.

In August at a rally, Mr. Trump said: “I’ll be the last one to use nuclear. I’ll be the last one, believe me.”

Then in September in a debate: “I think that once the nuclear alternative happens, it’s over. At the same time, we have to be prepared. I can’t take anything off the table.”

Mr. Trump at one time suggested he was open to the possibility of Japan and Saudi Arabia obtaining nuclear weapons. He said in March during a CNN town hall: “Maybe it’s going to have to be time to change... You have so many other countries now having it.”