John Bolton, a first-term Trump national security adviser who has since become an adversary, said the current administration made a "serious mistake" by not consulting allies before going to war.

"If you don't build your coalition before the war, it's pretty tough to do it while you're in it," said Bolton, who pleaded not guilty last fall to federal charges accusing him of emailing classified information to family members and keeping top secret documents at his Maryland home.

But he also cautioned European leaders against reflexively opposing Trump out of frustration with his lack of consultation. That, Bolton said, would be "juvenile and petulant."

Trump on his own terms

Trump's penchant to work on his own terms is not limited to the war.

Just this week, he said congressional approval of a ballroom he wants to build at the White House is "not necessary" despite a judge's ruling. He signed an executive order to create a nationwide list of verified eligible voters and to restrict mail-in voting.

In a first for a sitting president, he appeared in the courtroom of the Supreme Court as his administration tried to defend an executive order restricting birthright citizenship.

But as with the war, Trump's go-it-alone strategy at home is also confronting limits.

The Supreme Court struck down his far-reaching tariff program. Democrats quickly challenged his voting executive order in court and, despite his courtroom presence, the justices seemed skeptical of his bid to dismantle the Constitution's provisions providing birthright citizenship.

Then there is the uncertainty about the ballroom.

During private comments at an Easter lunch at the White House this week, Trump - ever the builder - seemed to lament the constraints on his job.

"I'm such a king I can't get a ballroom approved," he said to laughter from an audience that included Cabinet members and religious leaders. "I'm doing a lot. But I could be doing a lot more if I was a king."

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