Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, declined to speculate on what kinds of options the United States might consider in the event of a Russian invasion. But Milley, in some of his most detailed remarks on the crisis, underscored the importance of Ukraine’s sovereignty to Washington and to the NATO alliance.

“There are important national security interests of the United States and NATO member states at stake here if there were an overt act of military aggression by the Russians against an independent nation-state for 1991,” Milley said on a flight from Seoul. in Washington.

Ukraine says Russia has amassed more than 90,000 troops near their long common border. But Moscow has dismissed suggestions that it is preparing for an attack on its southern neighbor and has defended its right to deploy troops on its own territory as it sees fit.

The Kremlin previously annexed the Black Sea peninsula of Crimea to Ukraine in 2014, then backed rebels fighting Kiev government forces in the east of the country. This conflict has killed 14,000 people, says Kiev, and is still simmering.

Experts warn that an unchallenged Russian invasion could be destabilizing, creating ripple effects far beyond Ukraine at a time of growing concern over Chinese intentions towards Taiwan.

Milley declined to publicly state his estimate of the number of Russian forces near Ukraine, but suggested his concerns went beyond the raw number of Russian troops.

“I’m not going to tell you what we’re tracking and the indicators or the warnings from an intelligence perspective, but we’re tracking all of them,” Milley said. “And there’s enough out there now to cause a lot of concern, and we’ll continue to monitor.” Russia and Ukraine have centuries of common history and formed the two largest republics of the Soviet Union until its collapse in 1991. Moscow therefore sees its neighbor’s ambition to join NATO as a affront and a threat.

Since the start of the latest crisis, Moscow has demanded legally binding security guarantees from the West and assurances that NATO will not admit Ukraine as a member or deploy systems there. missiles to target Russia.

US Secretary of State Antony Blinken on Thursday warned Moscow of “significant costs” if it invaded Ukraine, urging his Russian counterpart to seek a diplomatic way out of the crisis.

Milley declined to speculate on whether Russian President Vladimir Putin might be emboldened by US President Joe Biden’s withdrawal from Afghanistan, saying, “You should ask Putin.” The August withdrawal ended the two-decade-old US war in unequivocal defeat, with the Taliban returning to power.

“I think it would be a mistake for any country to draw a broad strategic conclusion based on the American withdrawal from Afghanistan and then take that event and automatically apply it to other situations,” Milley said. .

He cited historical examples of former US presidents withdrawing troops from some places but ordering military action elsewhere. “So the United States is sometimes a difficult country for other countries to understand,” he said.

(Reporting by Phil Stewart; Editing by Jacqueline Wong and Simon Cameron-Moore)