MILAN — He was at it again this week.

First, President Vladimir V. Putin of Russia stopped in Belgrade, Serbia, for a military parade evocative of the Cold War. He questioned Kosovo’s sovereignty, took a swipe at President Obama in the Serbian news media and reached a summit meeting in Milan so far behind schedule that he was hours late for a private evening meeting with Europe’s most powerful leader, Chancellor Angela Merkel of Germany.

Nor was Mr. Putin done. When he left Ms. Merkel at roughly 2 a.m. Friday, his entourage streaked through Milan to the home of his friend and Italy’s former prime minister, Silvio Berlusconi. The men talked and enjoyed truffles until about 4 a.m., whereupon Mr. Putin departed, leaving him barely four hours before he joined European leaders, including Ukraine’s president, Petro O. Poroshenko, for a pivotal breakfast meeting.

For Mr. Putin, the helter-skelter blitz through Milan was only the latest demonstration of an unpredictable, often theatrical, diplomatic style that he has employed during the Ukraine crisis to throw his rivals off balance. This time he kept Ms. Merkel waiting late at night. Last month he upstaged President Obama on the eve of a NATO summit meeting focused on Russian aggression when he unexpectedly announced a seven-point peace plan for Ukraine — written on the back of a napkin as he flew for a state visit in Mongolia.

“He loves you and me and everybody else looking at him and trying to figure him out,” said Nina L. Khrushcheva, a professor of international affairs at the New School in New York and the great-granddaughter of Nikita S. Khrushchev. “He’s an exhibitionist.” She added, “He pushes the envelope all the time, and he gets away with it.”