Sources tell Threat Status that Mr. Trump has likely settled on Mr. Rubio — a hawk on China and a sharp Russia critic, but also a strong advocate of pursuing an end to the Ukraine war — as his nominee for secretary of state.

Sources also say Mr. Trump is close to picking Mr. Waltz to be his national security adviser. The former Green Beret, who served as a counterterrorism adviser to Vice President Dick Cheney after 9/11 and later opposed withdrawing large numbers of troops from Afghanistan without strict conditions, is also considered to be a tough critic of Beijing.

Separately, Mr. Trump says he’s nominating Rep. Elise Stefanik, the No. 4 House Republican, as U.S. ambassador to the United Nations. She served on Mr. Trump’s defense team during his first impeachment over his alleged quid pro quo over aid to Ukraine in exchange for an investigation into President Biden and his family’s ties to Ukraine. Asked about her selection, Ms. Stefanik told the New York Post that “America continues to be the beacon of the world, but we expect and must demand that our friends and allies be strong partners in the peace we seek.”

On another front, Mr. Trump is expected to select South Dakota Gov. Kristi Noem, a key supporter who had been considered as a possible vice presidential pick, to lead the Department of Homeland Security, naming a loyal ally to carry out the incoming administration’s aggressive border security and deportation plans.

For traditional allies, international organizations and countries willing to challenge his “America First” foreign policy, the election of Mr. Trump for another four years in the White House has already produced some nervous repositioning and sleepless nights.

But the jitters are not universal. Mr. Trump’s victory may bring some relief for the leaders of three authoritarian Southeast Asian nations caught in the influence struggle between the U.S. and China — Myanmar, Laos, and Cambodia.

Threat Status Special Correspondent Richard S. Ehrlich examines the situation from Thailand, reporting that some high-level regional sources believe Mr. Trump’s new administration will put less focus on human rights and democracy promotion than on security, economic opportunities and national interest.

That could create an easier standard to meet for East Asian countries weighing whether to align more closely with Washington in security alliances aimed at countering China’s push to achieve trade and military supremacy in the region.

Former Pentagon official Jim Townsend tells the Threat Status Weekly Podcast in an exclusive interview that U.S. allies in Europe have been caught off guard by Mr. Trump’s election win and are now scrambling to figure out how to get into the incoming president’s good graces.

“What we’ll see is that the various European nations have come beating a path right back to Mar-a-Lago until January 20, and then to the White House to try to curry favor and at least try to get on the good side,” said Mr. Townsend, who served as deputy assistant secretary of defense for European and NATO policy during the years leading up to the first Trump administration.

The podcast episode also looks at how the coming administration could approach the “axis of authoritarians” — China, Russia, Iran and North Korea. Mr. Townsend contends that Russian President Vladimir Putin sees Mr. Trump’s win as an opportunity, likely calculating that there’s “a four-year window here where he can try to accomplish some of his goals, which is to recreate a bit of what the former Soviet empire looked like.”

The Pentagon says U.S. forces have launched strikes against nine Iran-linked targets in Syria in response to several attacks on American troops in the region in recent days.

U.S. Central Command officials said in a statement Monday that the strikes by American forces were intended to degrade the ability of the Iran-backed militant forces to plan and launch future attacks on U.S. and coalition forces who are in Syria to conduct operations against the remnants of the Islamic State terrorist group.

Gen. Michael Erik Kurilla, commander of U.S. Central Command, said “attacks against U.S. and coalition partners in the region will not be tolerated” and that the Pentagon will continue to “take every step necessary to protect our personnel and coalition partners and respond to reckless attacks.”

Tom Homan, the president-elect’s new border czar, has delivered a stern warning to sanctuary cities, telling them to “get the hell out of the way” as the next administration comes for illegal immigrants. Mr. Trump has separately said he will tap Stephen Miller, an architect of his first administration’s firm posture on immigration, to be deputy White House chief of staff for policy.

Mr. Homan started his career as a Border Patrol agent and served in U.S. Immigration and Customs Enforcement before becoming acting director at the start of the first Trump administration. He was nominated to hold the position in full but met resistance in the Senate and never received a confirmation vote. In the intervening years, he has advocated for stiffer immigration enforcement and criticized President Biden.

In an interview with Fox News on Monday, Mr. Homan laid out an expansive effort to carry out Mr. Trump’s mass deportation promises. He said the administration will start with illegal immigrants who have criminal records or threaten national security. The estimated 1.1 million illegal immigrants who have refused to comply with deportation orders also will be priority targets.

• Nov. 12 — What Happened on Nov. 5: A Deep Dive into the Results of the Presidential and Congressional Races, Brookings Institution

• Nov. 12 — America’s Foreign Policy Future: A Post-Election Analysis, Stimson Center

• Nov. 13 — Event: Countering China’s Military Buildup: A Conversation with Sen. Eric Schmitt, American Enterprise Institute

• Nov. 13 — Competing with China on Critical Minerals, Hudson Institute

• Nov. 14 — What to Expect from Trump 2.0 for Korea? Center for Strategic and International Studies

• Nov. 22-24 — Halifax International Security Forum

• Dec. 7 — 2024 Reagan National Defense Forum, Ronald Reagan Presidential Foundation & Institute