The White House Ukraine summit on Monday brought as much uncertainty as it did optimism, with Mr. Trump, Mr. Zelenskyy and a group of European leaders unable to nail down specific parameters of security guarantees they’re seeking for Ukraine as part of any next-stage negotiations with Mr. Putin.

There was, however, optimism following the nearly all-day talks at the White House that an end-of-war agreement could eventually be reached. NATO Secretary-General Mark Rutte, who participated in the talks, said security guarantees for Ukraine were still under discussion. Mr. Trump did not provide specifics on the discussions. 

The Russian Foreign Ministry, meanwhile, warned on Monday that any foreign troops from NATO members providing security in Ukraine would be “unacceptable” and would be considered an “escalation” of the war. And it is still unclear whether Ukraine would concede to Mr. Putin’s demands that Russia retain large swaths of territory its troops have seized in eastern Ukraine. 

Chinese Foreign Minister Wang Yi is on a sensitive visit to New Delhi for talks with Indian Prime Minister Narendra Modi about the disputed Himalayan border region between India and China that has long been a point of tension and conflict between the two nuclear-armed neighbors nations — one of which represents the world’s largest democracy by population while the other is the world’s top communist power.

Beijing appears to have strategically timed Mr. Wang’s trip at a moment of friction between New Delhi and Washington following the Trump administration’s imposition of tariffs on India, a U.S. partner often seen as a counterbalance to China’s expanding influence in the Indo-Pacific. India is a member of the so-called Quad security alignment with the U.S., Australia and Japan, a grouping of democracies that acts as a buffer to Beijing’s muscle flexing in the region.

The Associated Press notes that India and China’s decades-old Himalayan border dispute worsened in 2020 after a deadly clash between the two countries’ troops in the Ladakh region. Some progress has been made since. Last year, India and China agreed to a pact on border patrols and withdrew additional forces along some border areas. Both countries continue to fortify their borders by building roads and rail networks.

A top military adviser to Iran’s supreme leader is warning that a new war with Israel could be imminent. The adviser, Yahya Rahim Safavi, told Iranian state media on Monday that Tehran “must be prepared for the worst-case scenario.”

Mr. Safavi questioned the strength of the ceasefire agreement with Israel that ended the 12-day war in June. “There is no protocol between us and Israel and the U.S. There is no ceasefire,” he said. “A new war with Israel could break out at any moment. We must be strong and prepared.”

The comments came as Tehran seeks to project strength after having its nuclear facilities pounded by U.S. and Israeli airstrikes. Other Iranian officials said Monday they have held negotiations with officials from the U.N. nuclear watchdog — the International Atomic Energy Agency — and plan to hold more talks in the coming days, signaling Tehran may seek to reengage in nuclear talks on the world stage.

Russia purportedly wants Crimea, which it has controlled since 2014, and the Donbas region of Ukraine, where it has about 88% control, Washington Times Commentary Editor Kelly Sadler writes in a column examining the ins and outs of Mr. Trump’s push for an end to the Ukraine war.

“Ukraine doesn’t want to reward Russia’s aggression by ceding any territory, and it wants security guarantees from the U.S. and European allies, if not full North Atlantic Treaty Organization membership,” Ms. Sadler writes. 

“The latter is a red line for Russia. Still, Russian President Vladimir Putin reportedly conceded last week that he would allow land-hallowed Ukrainian security forces, akin to the peace deal signed between North and South Korea in 1953,” she writes. “It’s the best deal Mr. Zelenskyy is going to get.”

By declaring that Taiwan’s defense capability must be calibrated entirely to the threat from Beijing, President Reagan “embedded deterrence into U.S. strategy,” according to Miles Yu, who assesses that the framework has “endured for more than four decades.

“Beijing’s actions today prove Reagan right. The [People’s Republic of China] has built a formidable military, deployed thousands of missiles aimed at Taiwan, and engaged in constant military harassment across the strait,” writes Mr. Yu, director of the China Center at the Hudson Institute and an opinion contributor to Threat Status.

“Reagan’s imperative was permanent because it was true: Peace in the Taiwan Strait is nonnegotiable, and coercion must never be rewarded. No use of force, ever,” he writes. “The duty now falls on President Trump, Congress and leaders of both parties. Uphold Reagan’s doctrine without hesitation or equivocation.”

• Aug. 19 — Counterterrorism and U.S. Strategy with Sebastian Gorka, Hudson Institute

• Aug. 20 — The Future of U.S.-Australia Critical Minerals Cooperation, Center for Strategic & International Studies

• Aug. 20 — Using AI to Understand Disaster Risks: New Tools, Shifting Frontiers, Chronic Challenges, Stimson Center

• Aug. 21 — Replicator and Beyond: The Future of Drone Warfare, Brookings Institution

• Aug. 26 — The Future of Naval Aviation: A Conversation with Vice Adm. Daniel L. Cheever and Lt. Gen. Bradford J. Gering, Center for Strategic & International Studies

• Aug. 26 — Reexamining the U.S.-South Africa Relationship, Foundation for Defense of Democracies