NATO's top military commander warned Monday that what he called the "lethal alliance" would destroy "anything and everything" supporting an attack on allied territory and "break" enemy warfighting systems to thwart any potential future Russian assault.

"Should the adversary choose to press the attack or commit his reserves, we will break the warfighting system engaged against us," U.S. Air Force Gen. Alexus Grynkewich said at the Warsaw Security Forum in Poland, in an apparent warning to Moscow.

"This includes not just the attacking force itself, but anything and everything that supports, sustains, and controls that force," he said during a panel titled "Theory of Victory: How Do We Achieve Military Success Against Russia in Deterrence and Defence?" on the first day of the forum. US ALLIES NEED TO SHOOT DOWN RUSSIAN AIRCRAFT TESTING NATO BOUNDARIES, CZECH PRESIDENT WARNS Grynkewich, NATO's supreme allied commander in Europe, also outlined a three-pronged strategy of "blocking, blunting and breaking" enemy forces, making clear that while NATO is a defensive alliance, it is prepared to respond decisively to an assault on any of its 32 members.

"If someone is foolish enough to attack us, we will fight," he said. "We will stop the attack and deny them the ability to achieve their objectives, whatever those might be. We will, in short, ensure any attack, against any ally, proves utterly futile."

The warning came amid heightened tensions between Russia and Western nations following a series of drone incursions and suspected sabotage operations that European countries have linked to Moscow.

"We stand here together in Poland today stronger than ever united in our common vision of a more balanced, more ready and more lethal alliance," Grynkewich also said.

European officials have accused Russia of waging a campaign of hybrid warfare involving sabotage, arson and cyberattacks, alongside increasingly provocative military activity near NATO territory.

I’M PRESIDENT OF ONE OF AMERICA’S MOST RELIABLE ALLIES. HERE’S HOW WE STAND UP TO RUSSIA In 2025, multiple Russian drones entered Polish airspace during a large-scale attack on Ukraine, prompting a response from Polish and allied aircraft. NATO launched Operation Eastern Sentry to strengthen defenses along its eastern flank.

Romania has also reported Russian drone incursions, while Estonia has accused Russian military aircraft of violating its airspace.

Grynkewich's remarks had followed a tense weekend between Russia and Ukraine, with Moscow launching fresh strikes against Ukrainian energy infrastructure despite diplomatic efforts to reduce hostilities.

President Donald Trump had announced that he had reached an agreement with Russian President Vladimir Putin to increase Russian diesel supplies to the U.S. and global markets.

ZELENSKYY ACCUSES PUTIN OF DEFYING TRUMP'S CEASEFIRE PUSH, SENDS POINTED MESSAGE TO WHITE HOUSE The reported agreement included a waiver of certain U.S. sanctions on Russian energy exports.

Zelenskyy went on to accuse Russia of continuing attacks on Ukrainian energy facilities, casting doubt on prospects for a broader ceasefire. The tensions have also been accompanied by recent nuclear warnings from Moscow.

On Sept. 30, Russia warned NATO that it could use nuclear weapons if the alliance attempted to isolate Kaliningrad, its heavily militarized Baltic Sea exclave between Poland and Lithuania.

In a diplomatic note obtained by Reuters, Moscow accused NATO of pursuing a "dangerous and reckless course" that carried "high risks of the outbreak of a direct armed conflict." According to the note, Russia warned it could use its full military arsenal, including nuclear weapons, to defend Kaliningrad and raised the possibility of strikes against decision-making centers in NATO countries at the outset of a conflict.

RUSSIA'S NEIGHBOR REVEALS PERSONAL APPEALS TO TRUMP AS US WEIGHS NATO TROOP PULLBACK IN EUROPE NATO Secretary-General Mark Rutte rejected the threats, emphasizing the alliance's defensive mission and calling on Moscow to end its war in Ukraine.

"Putin knows that he can never win from NATO," Rutte said during a Sept. 30 appearance at the Euronews Defence and Space Summit.

Putin has also maintained that Russia has no plans to attack European countries and wants peaceful coexistence with its neighbors.

Grynkewich did not mention Russia by name during his Warsaw address, but his warning appeared directed at Moscow and with NATO's 2022 Strategic Concept also identifying Russia as the most significant and direct threat to allied security.

"My theory of victory is simple: we will block the initial attack. If the attack persists, we will blunt it and prevent enemy advance," Grynkewich said on Monday.

"And if required, we will break the enemy's forces and the operational warfighting system that is arrayed against us." Grynkewich said NATO was already putting the strategy into action through military exercises, enhanced military readiness and investments in new capabilities.

"If attacked, we are ready to fight tonight, but we are not complacent," he said.

The general made clear that NATO's response would not necessarily be limited to enemy troops directly involved in an assault, but could extend to the broader military infrastructure enabling the attack.

Meanwhile, Trump has pressed European allies to increase defense spending and has questioned whether countries that fail to meet their obligations should expect U.S. protection.

Grynkewich sought to downplay concerns about Washington's commitment, recalling Trump's positive remarks about the alliance during the 2025 NATO summit in The Hague, Netherlands.

"I was in the room and I felt the love," Grynkewich said of the 2025 event.

"What I want to do is assure the one billion citizens of our alliance that we've got this. We know what we need to do. We know how we would do it," he added.

He also indicated a willingness to discuss suspected hybrid attacks more openly if individual NATO governments wanted him to address their concerns. "If a nation wants me to, I'm happy to talk about it," he said.

The Warsaw Security Forum brought together European political and defense leaders as the continent grappled with Russia's continuing war in Ukraine and the growing threat of confrontation along NATO's eastern flank.