The failure to protect NATO territory further increased anxiety about alliance solidarity, Russia’s intentions and Washington’s commitment to collective defense.

© Andreea Campeanu for The New York Times

A system of fuzzy borders, in which powerful states treat territory as negotiable and sovereignty as conditional, is not a viable alternative to the liberal world order.

The director of Britain’s electronic surveillance agency warned that Moscow was getting more brazen, adding that estimates suggested 500,000 Russian soldiers had been killed in the Ukraine war.

During a state visit, the Chinese and Russian leaders cast themselves as a stabilizing force in a world thrown into tumult by Washington.

China’s leader, Xi Jinping, welcomed President Vladimir Putin of Russia to Beijing, less than a week after a visit from President Trump.

With the upheaval in the Persian Gulf disrupting oil and gas supplies, Russia is looking to deepen its energy ties to China.

The lack of concrete agreements with Beijing shows the risks of President Trump’s personality-driven foreign policy, which rests on the belief that he can defend U.S. interests through charm and force of will.

The Russian leader will go to Beijing on Tuesday for talks with President Xi Jinping. The Kremlin said he had watched President Trump’s visit closely.

Watch an exchange between the two men in which the Chinese leader sought to signal exclusivity and name-dropped Russia’s president.

M. Gessen and Rachel Louise Snyder on the parallels between authoritarianism and domestic violence.