WARSAW — The crowd in Krasinski Square was loving it. “In the Polish people,” President Trump said, “we see the soul of Europe.”

Cheers. Shouts of joy. American flags of red, white and blue waved with red and white Polish ones across the crowded square, the epicenter of the Warsaw Uprising against the Nazis in 1944 and the site of a revered monument to that battle. Aging fighters from Poland’s struggle against Communism stood alongside new mothers pushing baby carriages, and the crowd spilled into the narrow side streets on the edge of Old Town.

If Mr. Trump was looking for a soft entry point for his second foray into Europe as president, after the stinging reaction of many European leaders to his first visit, he certainly found it.

“Poland is the first place in his foreign voyages where he can feel fully satisfied,” Janusz Sibora, an expert in diplomatic protocol, said in an interview with Gazeta.pl, a Polish website. “If he could, he would have taken this square back with him to Washington.”