Washington ? As President Trump embarks on his first overseas trip, he’s embracing the same defiant strategy adopted over a generation ago by an embattled predecessor, Richard Nixon. As scandal talks grow at home, Trump is licking his wounds, spurning his critics and looking for approval from foreign leaders who admire him for being a tough guy.

Trump’s combative early-morning tweets Thursday deflated any hope that he might see the appointment of Robert Mueller as special counsel as a chance to establish “regular order” and stabilize the roiling Russia scandal, in the words of GOP former national security adviser Stephen Hadley. Mueller’s steadying role would allow the nation to resume a measure of normal business while the investigation runs its course.

Trump’s instinct, instead, is to fight back against critics he believes are trying to destroy his presidency through the Russia investigation. “This is the single greatest witch hunt of a politician in American history!” he tweeted Thursday morning. The day before, he had declared in a graduation speech: “No politician in history — and I say this with great surety — has been treated worse or more unfairly.” His invocation to the graduates was: “Fight, fight, fight.”

Trump’s accomplishment after a cataclysmic first four months is that he’s still standing. His enemies, as he sees them, have taken their best shots and missed. He’s taken some roundhouse swings of his own, losing some GOP support in Washington in the process. But his national base of support hasn’t budged much and remains at about 40 percent.

Trump and his inner family circle seem, if anything, to be hardening their stance. Rather than regretting the firing of FBI Director James Comey, Trump seems more convinced than ever that Comey deserved to be sacked for writing the memos about conversations with the president that are now central to the investigation.

For Trump, the Russia investigation still appears to be a zero-sum game — the political equivalent of kill or be killed. For the country, this confrontational stance promises continuing bitterness and a deepening confrontation, despite the widely applauded appointment of Mueller to oversee the investigation.

What’s unfortunate, from a foreign policy standpoint, is that Trump’s inability to calm the Washington turmoil threatens to overshadow his foreign trip and undermine some potentially important gains. The centerpiece of the trip is Trump’s visit to Saudi Arabia, where he will publicly embrace the reform agenda of Saudi Deputy Crown Prince Mohammed bin Salman and moderate Arab allies, such as Sheikh Mohammed bin Zayed, the crown prince and military leader of the United Arab Emirates.

The White House, disorganized on so many topics, has carefully prepared the agenda for this trip. The Saudi hosts (joined by numerous other Arab leaders) will sign pledges promising to ban financing of extremist groups, including by private individuals. If that happens, it could be a significant breakthrough, adding a formal legal prohibition against support for terrorism.

Trump will also help open a new Saudi center for combating violent extremism that will use advanced computer tools to penetrate jihadist networks. The center is a personal project of Mohammed bin Salman, and it brings the deputy crown prince deep into the security arena traditionally dominated by his rival, Crown Prince Mohammed bin Nayef, the minister of the interior who is nominally his senior but whom he seems to have eclipsed in power.

Trump’s aim is to refurbish the U.S.-Arab alliance based on shared distrust of Iran. In a speech, he is expected to say that the Mideast struggle isn’t between Islam and the West, but between good and evil. He’ll announce a broad military alliance that White House aides are characterizing as an “Arab NATO” — quite a leap for a president who a few months ago was declaring NATO “obsolete.” To ease U.S. wariness of new Middle East entanglement, the Saudis will announce a plan to buy $109 billion in U.S. military equipment, allowing Trump to claim he’s creating U.S. jobs.

Senior Arab officials see the Trump visit as a big bet on an American re-engagement in the region that will empower reformers in Saudi Arabia, the richest and most powerful Sunni Arab state. If Saudi reformers gain traction, it could be a “hinge” event for the region. But Arab officials hope that Trump’s political problems at home won’t put this promising project at risk.

Domestic scandals can have the odd effect of encouraging diplomacy abroad. President Nixon made major peace deals in the Middle East after the Watergate debacle began. But even so, that story didn’t end happily for Nixon or America.

— David Ignatius is a columnist for Washington Post Writers Group.