Analysis by Stephen Collinson, CNN

Updated 0638 GMT (1438 HKT) November 21, 2018

Washington (CNN)It is the Trump doctrine laid bare.

By letting Saudi Arabia get away with the murder of US-based journalist Jamal Khashoggi, the President sent a message of startling clarity about how the United States will conduct its business in the world.Refusing to break with Saudi strongman Mohammed bin Salman over the killing in the Saudi consulate in Istanbul, Trump effectively told global despots that if they side with him -- Washington will turn a blind eye to actions that infringe traditional US values.

But more than that, by stressing the "billions" of dollars in Saudi investment in the US, Trump made clear that Washington has a price, that principles that generations of Americans have cherished, are for sale."The world is a very dangerous place! ... It's called America First!" Trump wrote in a statement, effectively repudiating the concept of American Exceptionalism, the idea that the US is embarked on a unique, moral mission exemplified by support for freedom, democracy and universal values.The President's decision Tuesday to answer the long-running question of how he will respond to the murder of the Washington Post columnist revealed other pillars of the Trump doctrine in one of the most colloquial and oddly stylistic statements on US foreign policy ever written.It showed a President willing to ignore and prejudge US intelligence assessments that conflict with his political goals.His readiness to offer impunity to Saudi Arabia represented another blow to the international rule of law and global accountability, concepts Trump has shown little desire to enforce in nearly two years in office.

The President's statement is certain to trigger a fierce clash with Congress, where there is bipartisan momentum to punish Saudi Arabia.Republican Sen. Bob Corker of Tennessee, chairman of the Senate Foreign Relations Committee, blasted Trump's response."I never thought I'd see the day a White House would moonlight as a public relations firm for the Crown Prince of Saudi Arabia," he tweeted on Tuesday.And it may deepen the estrangement between Trump and the intelligence community, given his rejection of a CIA assessment that the crown prince knew about the killing of Khashoggi.

No room for misunderstandingTrump's statement was remarkable because it was not just an explanation of Saudi policy. He consciously used the moment to deliver a lesson about how he would wield American power as he redefined the nation's role in the world.He essentially argued that although the murder of the Washington Post journalist was "terrible" and could not be condoned, it did not merit the disruption of a strategic relationship he has elevated to extraordinary levels."We're not going to give up hundreds of millions of dollars in orders and let Russia and China have them ... it's a very simple equation for me. I'm about make America great again," he told reporters.

His decision appeared to suggest that as long as a foreign power enriches the United States it would face no censure for despotic behavior.Perhaps Trump should get marks for frankness.Many Presidents have wrestled with the tension between American values and the trade-offs required by realpolitik. Often Washington's actions -- in the Vietnam War for instance or in the war on terror, have been seen by outsiders as falling well short of the lofty principles it has preached to others.American relations with Saudi Arabia, a key power broker in the Middle East and crucial oil producer vital to the global economy have often fallen on the hypocritical side of this line.But the pull of the idea that America is leading a group of like-minded nations wedded to democratic, enlightened principles was always strong and while waxing and waning under different Presidents it never disappeared.Yet Trump is getting rid of any pretense. As Secretary of State Mike Pompeo put it: "It's a mean nasty world out there," in an apparent sign that Washington is ready to play the same cynical game as Beijing, Moscow and other challengers to Western power who reject the US-backed international system.

Trump's pivot shocked many more conventional politicians in Washington."I am concerned about our standing in the world and what it says about the United States," Republican Rep. Francis Rooney of Florida told CNN's Brianna Keilar."From our very beginnings we have been a country founded on important principles of freedom, rule of law. The Declaration of Independence kind of sets the road map. And I don't think we want to back up on that and cut a break for Saudi Arabia murdering someone," Rooney said.Yet Trump's argument will please his supporters, who reject the premise of the international liberal order and multinational institutions, and believe the previous Obama administration was ineffectual.And it represented the latest show of force from a President who is showing signs of breaking free from any remaining restraints, and is increasingly confident in a course that has sown historic disruption.