ANALYSIS: Corker feud opens gash between Trump and GOP establishment This is no mere war of words.

 -- Sen. Bob Corker was trying.

The Tennessee Republican was trying to work inside the system. He engaged with a president and a White House that do nothing in predictable ways, in navigating foreign policy around North Korea, Iran, Russia and fighting terrorism.

He was trying to work around the system. He cultivated a network of allies inside and outside the Trump administration to influence policy -- often by maneuvering to prevent what he saw as bad outcomes more than even getting his preferred way.

That all collapsed over the weekend, lost in a haze of tweeted insults and an interview that may mark a critical pivot point in President Donald Trump’s relationship with Corker as well the broader Republican establishment.

This is no mere war of words between Trump and an erstwhile ally. It’s a no-turning-back moment between the president and one of the most respected members of the Republican foreign policy elite -- the chairman of the Senate Foreign Relations Committee, a deliberate thinker and potential peacemaker, and a man Trump himself considered for a spot on his ticket or in his Cabinet.

The stakes -- war and peace, America’s standing in the world, and nuclear showdowns -- literally could not be higher. And there’s no cleaning it up with a few more tweets.

The deterioration of Trump’s relationship with Corker figures to have long-term consequences for the president’s governing agenda, his credibility with the conservative base, and the checks and balances that have thus far constrained him from pursuing some of his more impulsive notions.

Corker’s interview with The New York Times on Sunday was extraordinary on several levels. He essentially called Trump a liar whose reckless behavior could leave the nation “on the path to World War III” by means of following up his tweet about the White House being an “adult day care center” where someone seems to have missed a supervisory shift.

But in the end, the most damning blow delivered by Corker was his declaration that there’s no strategy behind the scattershot way Trump conducts his foreign policy. Corker’s judgment is that there is no method, only madness.

“A lot of people think that there is some kind of ‘good cop, bad cop’ act underway, but that’s just not true,” Corker told the Times.

Trump’s behavior has already had real-world consequences, Corker continued: “In several instances, he’s hurt us as it relates to negotiations that were underway by tweeting things out.”

After engaging in a Twitter volley over the weekend by claiming Corker decided to retire because he wasn’t getting Trump’s endorsement -- Corker claims the president did, in fact, offer his endorsement -- Trump went silent on the Corker front early Monday.

White House counselor Kellyanne Conway told Fox News that Corker’s outburst was “incredibly irresponsible” and that it “adds to the insulting that the mainstream media and the president's detractors” aim toward the president.

But Corker does not seem likely to change course because of lectures on Twitter etiquette from this White House. This was a considered move by a man freed of the need to run for reelection, and whose frustration ebbed and flowed before bursting over this past weekend.

That man will continue to occupy a vital seat for the advancement of the Trump agenda. The future of the Iran nuclear deal -- which Trump is poised to try to undo this week -- will land in his committee. Corker had already signaled skepticism about the tax overhaul that might be Trump’s last best hope for a legislative victory this year.

The president’s Senate enemies’ list appears likely to grow. Aside from the president’s public chiding of Senate Majority Leader Mitch McConnell, R-Ky., word emerged over the weekend that Trump’s former top political adviser, Steve Bannon, is seeking primary challengers against virtually every Senate Republican on the ballot next year.

Trump has turned name-calling episodes into working partnerships before. Almost on cue, he spent Columbus Day golfing with Sen. Lindsey Graham, R-S.C., whom he once mocked as a “lightweight” and an “idiot.” Famously, Trump once read out Graham’s private cellphone number at a campaign event, urging supporters to “try it.”

But, in Corker’s telling, damage to the country could be done long before any tee times are set. This fight involves noise, but also the threat of very real actions.