The Philippines and Taiwan are set to cooperate on protecting undersea cables from the threat of Chinese sabotage in the strategic Bashi Channel. The development underscores how the two U.S. security partners are confronting Chinese “gray zone” operations, ranging from maritime harassment and aerial intimidation to cyberattacks and damage to undersea infrastructure.

The 2022 destruction of the Nord Stream pipelines, which carried Russian gas to Europe via the Baltic, thrust seabed warfare into the public gaze. In an ongoing case, German authorities have accused a Ukrainian special forces officer of sabotage.

Chinese vessels in recent years have conducted seabed surveys of East Asian and Australasian waters. Experts say these surveys provide useful data for submarine deployments, as well as reconnaissance for potential operations to cut seabed cables and take out underwater sensors.

Voters will decide Sunday whether Brazil will be the latest South American nation to embrace closer ties with the U.S. and Mr. Trump, who is backing conservative, pro-Washington Sen. Flavio Bolsonaro, the eldest son of former President Jair Bolsonaro, in the presidential runoff race against the leftist incumbent, Luiz Inacio Lula da Silva.

Threat Status Special Correspondent Joseph Hammond writes that Mr. Trump has championed a more forceful role for the U.S. in the Western Hemisphere, including ramping up strikes on drug traffickers, enforcing a suffocating blockade of Cuba, executing direct military intervention and effecting regime change. Ousted Venezuelan leader Nicolas Maduro is now awaiting trial in the United States.

Pro-Trump conservatives have racked up a string of election victories across Latin America, including Jose Antonio Kast in Chile, Nasry Asfura in Honduras and the Trump-endorsed Abelardo de la Espriella in Colombia. Threat Status recently went inside the so-called “Donroe Doctrine” approach to the hemisphere in an exclusive video interview with longtime regional expert Michael Shifter.

Secretary of State Marco Rubio said this week that he and Mr. Trump are trying to convince a reluctant Chinese government to join three-way talks with the United States and Russia on nuclear arms.

Mr. Rubio told reporters during a trip to India that he wants Beijing’s participation in strategic nuclear arms talks, which are currently stalled between Washington and Moscow over Russia’s war in Ukraine. He said the Chinese in the past rejected arms talks on what U.S. military leaders have called the most alarming nuclear warhead and strategic weapons buildup since the Cold War.

The last remaining nuclear arms control agreement between Washington and Moscow — the Strategic Arms Reduction Treaty (START) — expired in February against a backdrop of a Chinese nuclear arsenal that is growing rapidly.

The defense secretary has banned military personnel from using nonpublic information to bet on U.S. military operations through online prediction market platforms, such as Polymarket or Kalshi. A Pentagon memo to senior military leadership said the prohibition applies whether the transaction uses classified or unclassified information.

“Our enemies watch movements in these markets. When an American service member, intelligence professional, or other [Defense Department] civilian engages in a financial transaction on a military outcome, they create a signal,” Mr. Hegseth wrote in the Oct. 20 memo. “That signal can be aggregated, correlated and exploited by hostile foreign intelligence services to anticipate our moments, targets and timing,” he said.

A U.S. Army special forces soldier was indicted in April on charges of using classified information about the capture of Venezuelan leader Maduro to make more than $400,000 on a prediction market. Master Sgt. Gannon Ken Van Dyke pleaded not guilty and was released on bond.

In this fall’s defense budget deliberations, Congress “must fully fund the F-35B Lightning II aircraft,” warns retired Marine Lt. Gen. Karsten “Hazel” Heckl, who argues in an op-ed for The Washington Times that “America simply cannot afford disruption or delay in procuring this fighter.

“This specific variant of the F-35 — one with vertical takeoff-and-landing capability — plays an outsized role in the U.S. Marine Corps’ strategy to deter and, if necessary, defeat aggression by China,” Gen. Heckl writes. He served as deputy commandant for combat development and integration and commanding general of Marine Corps Combat Development Command from 2021 to 2024, where he was the Marine Corps’ top requirements officer. 

“The F-35B is survivable in combat, but whether it is a match for Beltway budget machinations is an open question,” he writes. “Let us hope wisdom prevails and that procuring more F-35B fighters is high on the congressional and Pentagon priority lists.”

• Oct. 26 — U.S.-Republic of Korea Shipbuilding Cooperation: Taking Stock and Charting the Next Steps, Stimpson Center

• Oct. 27 — Chemistry of Combat: Rebuilding America’s Energetics Base, Hudson Institute

• Oct. 28-29 — China’s Power: Up for Debate 2026, Center for Strategic and International Studies

• Oct. 30 — Gen. Dagvin R.M. Anderson, Commander of U.S. Africa Command, on U.S. Strategy and Security in Africa, Atlantic Council

• Nov. 16 — The Black Sea Blueprint for Taiwan: Lessons in Asymmetric Naval Warfare, Foundation for Defense of Democracies

• Nov. 17 — Special Threat Status Event: The Golden Age of Space, Threat Status

• Nov. 20-22 — Halifax International Security Forum in Nova Scotia, Canada, HFX