Donald Trump’s tendency to shoot first on Twitter and ask questions later may have made for an amusing distraction during the early months of his election campaign. But it has become something significantly more serious now that he is about to become president.
In just the past few weeks, Trump has caused a diplomatic incident with China over his recognition of Taiwan as an independent state, and has triggered multi-billion-dollar slides in the market value of companies like Lockheed Martin and Boeing by criticizing their products on Twitter.
On Thursday, this loose-cannon approach to Twitter appeared to hit a new low, when the president-elect committed the U.S. to a nuclear arms race.
As soon as Trump’s commitment to “greatly strengthen” the U.S. nuclear capability hit the social network, analysts from both sides of the political fence started working on what he might mean. New York Times writer Max Fisher did an entire story pondering the potential significance of the tweet, and what it might suggest about the soon-to-be president’s strategy.
Get Data Sheet, Fortune’s technology newsletter.
On Friday morning, however, Trump himself clarified what he meant in a phone call with Morning Joe talk-show host Mika Brzezinski—whose announcement of the news took on a somewhat bizarre tone due to the fact that she and co-host Joe Scarborough were wearing their pajamas in front of a roaring fire.
Brzezinski said that when he was asked about the tweet during their off-air phone conversation, Trump said: “Let it be an arms race. We will outmatch them at every pass and outlast them all.”
It’s still unclear why the president-elect decided to tweet his comment about nuclear weapons in the first place. The only related news that may have triggered such a response was a comment by Russian President Vladimir Putin that his government planned to boost its investment in nuclear weapons.
Following his tweet and interviews, Trump’s staff spent a considerable amount of time trying to spin his remarks as not being intended to start a nuclear arms race.
These are all of Trump’s potential conflicts of interest:
“He’s going to ensure that other countries get the message that he’s not going to sit back and allow” them to engage in nuclear proliferation, Trump spokesman Sean Spicer told NBC. “And what’s going to happen is they will come to their senses, and we will all be just fine.”
Daryl Kimball, executive director of the Arms Control Association — a group devoted to fighting nuclear proliferation — said it was “completely irresponsible for the president-elect or the president to make changes to U.S. nuclear policy in 140 characters and without understanding the implications of statements like ‘expand the capacity.”