At home, President Trump is ordering up investigations into his political opponents and finding creative ways to use his executive power to ruin the lives of even some of his milder critics.

Abroad, Mr. Trump has sent a different message: Let bygones be bygones. Even if those bygones involved trying to assassinate him or working with Al Qaeda.

In a series of speeches and off-the-cuff remarks during the first major foreign trip of his second term, Mr. Trump has told audiences in the Middle East that he is willing to set the past aside in the interests of peace and profit.

“I have never believed in having permanent enemies,” Mr. Trump said in a speech on Tuesday at the Saudi-U.S. Investment Forum in Riyadh. “I am different than a lot of people think.”

His statement about permanent enemies related to his outreach to Iran — a government accused of plotting to assassinate him after he left office. (Iran denies this.) But just a little while later, in the same speech, Mr. Trump offered a more surprising olive branch.

He announced he would lift U.S. sanctions on Syria, throwing an economic lifeline to a country ravaged by decades of repression, civil war, terrorism and poverty exacerbated by international isolation.