Trump's new nuclear doctrine

The Trump administration on Friday announced it will continue much of the Obama administration's nuclear weapons policy, but take a more aggressive stance toward Russia. It said Russia must be persuaded it would face "unacceptably dire costs" if it were to threaten even limited nuclear attack in Europe.

The sweeping review of US nuclear policy does not call for any net increase in strategic nuclear weapons, a position that stands in contrast to President Donald Trump's statement, in a tweet shortly before he took office, that the US "must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes." In his State of the Union address Tuesday, he made no mention of expansion, though he said the arsenal must deter acts of aggression.

A 74-page report summarizing the review's findings calls North Korea a "clear and grave threat" to the US and its allies. It asserts that any North Korean nuclear attack against the US or its allies will result in "the end of that regime."

"There is no scenario in which the Kim regime could employ nuclear weapons and survive," it says.