Secretary of State Marco Rubio met with Russian Foreign Minister Sergey Lavrov in Malaysia Thursday at a meeting of the Association of Southeast Asian Nations. The meeting put the Russia-Ukraine war at the center of a trip that was meant to strengthen alliances in Southeast Asia.

Marco Rubio wants to bolster ties with Asia to counter China’s sway, but President Trump’s tariff threats have nations asking why they should align with Washington.

The meeting is set to take place shortly after the U.S. resumed some shipments of defensive weapons to Ukraine following a pause — ostensibly for the Pentagon to review domestic munitions stocks — th...