What can we expect this year?

A significant shift in American foreign policy under President Trump has further changed the dynamic.

Seth G. Jones, a senior adviser at the Center for Strategic and International Studies, said the conference would reflect a world in which the United States and Europe are increasingly at odds.

The Americans have traditionally “been the harbingers of the growth and protection of the order,” Mr. Jones said. “And now we have the U.S., at least some of the U.S. figures like the president, questioning that.”

On the agenda for the 2019 conference are discussions of the future of the European Union; trade and international security; arms control; and the implications of power struggles between the United States, China and Russia. Senior officials from all of those countries will attend.

Divisions between the United States and Europe on several security issues, including the Americans’ abandonment of the Iran nuclear deal, have placed the allies at odds. Recent American decisions to pull back from conflicts abroad — with Mr. Trump announcing the withdrawal of troops in Syria and plans to downsize America’s role in Afghanistan — have left European allies wondering who will step in.

“There is a broader question in Europe, including among countries gathering in Munich, about what the U.S. role in the world is,” Mr. Jones said. “It’s not necessarily isolationist policy, but definitely one operating with much more international restraint than previous administrations. And who fills that vacuum?”

America’s changing role and internal divisions will be on display.

The United States is bringing its largest-ever delegation to the conference, with Vice President Mike Pence and Patrick Shanahan, the acting defense secretary, representing the Trump administration. A congressional delegation includes the House speaker, Nancy Pelosi.