>> America first, folks, America first.>> It became one of Donald Trump's signature battle cries on the trail. But 100 days into his presidency, America first is colliding with harsh reality. From Syria
North Korea, forces beyond his control pulling Trump's gaze away from home and his core principles, and worrying some of his true believers.
Jim Oliphant is on the story.>> Well, as a candidate, Trump touted staying out of foreign entanglements, border security, and ripping up trade deals to make them more favorable to American companies. Well, as they say in the commercials, life comes at you fast. And like any President, Trump has had to deal with some crises that he wasn't counting on, namely, Syria, North Korea.
And it's forced him to take much more of an aggressive posture.>> In Syria, Trump firing 59 cruise missiles at one of Bashar al-Assad's air bases after an horrific gas attack. And sending what he called, an armada, led by the USS Carl Vinson carrier force, to show off American muscle in the face of Kim Jong-un's rising nuclear threat.
>> Now, that's alarmed some of his supporters who are very wary of interventionism and getting involved in another war.>> Trump also changing his tune on one of his biggest campaign targets, China. Tweeting about potential trade concessions in return for China's help with North Korea. But with the 100 day marker in sight, Trump is giving America first another push.
>> Lately, we've seen the more populist Trump rear his head again, where he's talking about slapping tariffs on imported goods, and trying to level the playing field for American merchants. We've seen this with steel and with wood, more lately aluminum. And this is Trump basically trying to live up to the promises that he made during the campaign about supporting American business.
>> But Oliphant says Trump's first 100 days have clearly changed the game.>> Well, look, America first is a great thing to talk about. It's a nice slogan for a campaign. But in practicality, it's something very hard to do given the United States' role In the world. And Trump has already been tested on several fronts.
And I think he has sort of found, too, that he might like being a little bit more of a globalist. Reuters recently spoke to more than two dozen Trump supporters. And they're not retreating from that. And he's playing to that still. In their minds, he's doing a great job.
>> A pretty big shock to the system.