A White House lurching from crisis to crisis appeared close to complete meltdown Friday, as Donald Trump's staff struggled to limit damage from two impulsive moves with far-reaching consequences.

Trump's off-the-cuff enticement of a global trade war and calls for limits on the constitutional right to bear arms cleaved a schism between the mercurial president and his Republican backers, sparked a stock market sell-off and prompted threats of retaliatory sanctions from across the globe.

Angered by the announced departure of confidant Hope Hicks, financial scandals surrounding son-in-law Jared Kushner and the ongoing investigation into his campaign, Trump thumbed his nose at advisors' warnings and announced punitive steel and aluminum tariffs.

"When a country (USA) is losing many billions of dollars on trade with virtually every country it does business with, trade wars are good, and easy to win," Trump tweeted Friday.

Officials made no effort to disguise that the decision -- which will bring legal action -- had short circuited internal deliberations and preempted the administration's own determination about whether the step was lawful.

The tariffs are an extension of Trump's decades-long crusade against America's terms of trade, but infuriated allies in Canada, Europe, Asia and Latin America.

The internal blowback was swift, with renewed rumors that top economic advisor Gary Cohn -- who had been infuriated by Trump's unwillingness to condemn neo-Nazis -- was ready to walk.

Wall Street insiders -- who have embraced Trump's tax cuts and laissez faire approach to regulation -- expressed disbelief at the policy, but also disbelief at a White House that appears to have careened off the rails.

Trump's tweets came only hours after he blindsided Republicans by advocating raising age limits for gun ownership, tightening background checks and seizing some weapons without due process.

Republicans have shown themselves to be strikingly tolerant of Trump's rhetorical and even alleged moral transgressions, but that gun heterodoxy was a step too far for most.

"Strong leaders don't automatically agree with the last thing that was said to them," snapped Republican Senator Ben Sasse. "We have the Second Amendment and due process of law for a reason.”