– Barack Obama's extended post-presidential vacation is about to end. After spending weeks in French Polynesia — including time on the yacht of movie mogul David Geffen along with Bruce Springsteen, Tom Hanks and Oprah Winfrey — Obama will return to Chicago on Monday for his first public event as a former president.

His self-imposed silence since Inauguration Day will end with a series of events over the next four weeks. A Monday town hall-style meeting with students at the University of Chicago will be followed by an awards ceremony in Boston; a series of public remarks as well as private paid speeches in the United States and Europe; and an appearance at the Brandenburg Gate in Germany with Chancellor Angela Merkel.

And yet, Obama's supporters, who have been waiting eagerly for the former president to respond to his successor's accusations and policy reversals, are likely to be disappointed.

Even as he witnesses President Donald Trump's relentless and chaotic assault on his legacy, Obama remains stubbornly committed to the idea that there is only one president at a time. Those closest to him say the former president does not intend to confront Trump directly on immigration, health care, foreign policy or the environment during any of his events.

"Why are we not hearing from him? We've got to hear from him," said Sarah Kovner, a New York City Democratic activist who raised more than $1 million for Obama's campaigns. "Democrats are desperate."

"Everything that Trump is doing really requires a response," Kovner added.

Obama and a small cadre of former White House aides in his Washington office know that anything he says in public, no matter how veiled, will be interpreted as criticism of Trump.

Obama's aides say he will also not criticize Trump in his private paid speeches. The aides would not say how much Obama will be paid per speech, but former President Bill Clinton averaged more than $200,000 per speech between 2001 and 2015; former President George W. Bush is reportedly paid $100,000 to $175,000 for each appearance.

Aides have rejected the idea that Obama should actively wage a public feud against Trump, with whom he has not spoken since the inauguration. They believe that such a fight would give the current president the high-profile political foil he wants to further energize his conservative supporters.

Obama has also concluded that his voice is not essential in the daily back-and-forth. His aides note that a new level of civic activism among Democrats eager to challenge Trump has emerged without much encouragement from the former leader of the Democratic Party. And many of Trump's attacks on Obama-era policies — like the health care law — have so far failed or stalled.

Instead, Obama is preparing remarks that focus on broader themes he hopes will keep him above the cable-television combat and the Capitol Hill debates: civic engagement, the health of the planet, the need for diplomacy, civil rights and the development of a new generation of young American leaders.

In the weeks after winning the White House, Trump assembled a Cabinet intended to eradicate most of Obama's accomplishments. Once in office, Trump accused the former president of wiretapping him, without offering any evidence, and he said on Twitter that Obama was a "Bad (or sick) guy!" Trump also accused his predecessor of being behind national security leaks, and he all but blamed Obama for Syria's chemical weapons attacks.

The pressure on Obama to enter the fray has steadily increased as Trump moved to reverse Obama-era environmental protections, ban travel from several predominantly Muslim countries, abandon trade deals, eliminate progressive regulations and install a conservative Supreme Court justice.

Through it all, Obama has stayed mostly silent. (During a conference call with thousands of despairing supporters a week after the election, Obama said only: "Don't mope. And don't get complacent.")

On Monday, the former president will return to his adopted hometown, Chicago, for a conversation with a half-dozen young people and a question-and-answer session with an audience of college students.

As he begins his paid speeches, Obama, who is represented by the Harry Walker Agency, is scheduled to engage in a private conversation with the historian Doris Kearns Goodwin for the employees of the A&E television network.

On May 7 in Boston, Obama will accept the Profile in Courage Award given annually by the John F. Kennedy Library Foundation. He will deliver a speech at the library's black-tie dinner. His remarks — built around the theme of what courage means in today's world — will not name Trump.

Later in May, Obama will travel with his White House chef and friend, Sam Kass, to Italy for a speech at the Global Food Innovation Summit about the effect of climate change on food sources. On May 25, Obama is to deliver a speech at the Brandenburg Gate in Berlin, joined by Merkel, a close ally during his time in office.

In both European cities, Obama will also deliver paid speeches.