NATO faced rebukes from Moscow and Beijing on Thursday after it declared Russia a "direct threat" and said China posed "serious challenges " to global stability.
During a summit in Madrid, the Western military alliance described a world plunged into a dangerous phase of big-power competition and facing myriad threats, from cyberattacks to climate change.
NATO Secretary-General Jens Stoltenberg said as the summit wrapped up Thursday that member nations agreed on a "fundamental shift in our deterrence and defense" and sent Moscow a clear message that the alliance had a firm line drawn on its eastern frontier.
"We live in a more dangerous world and we live in a more unpredictable world, and we live in a world where we have a hot war going on in Europe," Stoltenberg said. "At the same time, we also know that this can get worse if this becomes a full scale war between Russia and NATO."
Stoltenberg continued: "We want to remove any room for miscalculation, misunderstanding in Moscow, about our readiness to protect every inch of NATO territory. That's NATO's core responsibility."
Over their three days of talks in Spain, NATO leaders formally invited Finland and Sweden to join the alliance, after overcoming opposition from Turkey. If the Nordic nations' accession is approved by the 30 member nations, it will give NATO a new 800-mile border with Russia.
Russian President Vladimir Putin warned he would respond in kind if the Nordic pair allowed NATO troops and military infrastructure onto their territory. He said Russia would have to "create the same threats for the territory from which threats against us are created."
Estonian Prime Minister Kaja Kallas said Putin's threats were "nothing new."
"Of course, we have to expect some kind of surprises from Putin, but I doubt that he is attacking Sweden or Finland directly," Kallas said as she arrived at the summit's conference center venue. "We will see cyberattacks definitely. We will see hybrid attacks, information war is going on. But not the conventional war."
China accused the alliance of "maliciously attacking and smearing" the country. Its mission to the European Union said NATO "claims that other countries pose challenges, but it is NATO that is creating problems around the world."
NATO leaders turned their gaze south for a final summit session Thursday focused on Africa's Sahel region and the Middle East, where political instability — aggravated by climate change and food insecurity sparked by the war in Ukraine — is driving large numbers of migrants toward Europe.
"It is in our interest to continue working with our close partners in the south to fight shared challenges together," Stoltenberg said.
But it was Russia that dominated the summit. Stoltenberg said Moscow's invasion of Ukraine had brought "the biggest overhaul of our collective defense since the end of the Cold War."
The invasion shattered Europe's peace, and in response NATO has poured troops and weapons into Eastern Europe on a scale unseen in decades. Member nations have given Ukraine billions in military and civilian aid to strengthen its resistance.
Ukrainian President Volodymyr Zelenskyy, who addressed the summit by video link, asked for more. He urged NATO to send modern artillery systems and other weapons and warned the leaders they either had to provide Kyiv with the help it needed or "face a delayed war between Russia and yourself."
"The question is, who's next? Moldova? Or the Baltics? Or Poland? The answer is: all of them," he said.
At the summit, NATO leaders agreed to dramatically scale up military force along the alliance's eastern flank, where countries from Romania to the Baltic states worry about Russia's future plans.
They announced plans to increase almost eightfold the size of the alliance's rapid reaction force, from 40,000 to 300,000 troops, by next year. The troops will be based in their home nations but dedicated to specific countries in the east, where the alliance plans to build up stocks of equipment and ammunition.
U.S. President Joe Biden, whose country provides the bulk of NATO's firepower, announced a hefty boost in America's military presence in Europe, including a permanent U.S. base in Poland, two more Navy destroyers based in Rota, Spain, and two more F35 squadrons in the U.K.
The expansion will keep 100,000 troops in Europe for the foreseeable future, up from 80,000 before the war in Ukraine began.
President Biden said Putin had believed NATO members would splinter after he invaded Ukraine, but the Russian leader got the opposite response.
"You're gonna get the NATO-ization of Europe," President Biden said. "And that's exactly what he didn't want, but exactly what needs to be done to guarantee security for Europe."
Still, strains among NATO allies have emerged as the cost of energy and other essential goods has skyrocketed, partly because of the war and tough Western sanctions on Russia. There also are tensions over how the war will end and what, if any, concessions Ukraine should make.
Money remains a sensitive issue — just nine of NATO's 30 members currently meet the organization's target of spending 2% of gross domestic product on defense.
Britain, one of the nine, announced a further 1 billion pounds ($1.21 billion) in military support to Ukraine on Thursday,
At what Stoltenberg called a "transformative" summit, the leaders published NATO's new Strategic Concept, its once-a-decade set of priorities and goals.
The last such document, in 2010, called Russia a "strategic partner." Now, NATO is accusing Russia of using "coercion, subversion, aggression and annexation" to extend its reach.
The 2010 document made no mention of China, but the new one addressed Beijing's growing economic and military reach.
"China is not our adversary, but we must be clear-eyed about the serious challenges it represents," Stoltenberg said on Wednesday.
NATO said that China "strives to subvert the rules-based international order, including in the space, cyber and maritime domains" and warned of its close ties with Moscow.
The alliance said, however, that it remained "open to constructive engagement" with Beijing.
China shot back that NATO was a source of instability and vowed to defend its interests.
"Since NATO positions China as a 'systemic challenge,' we have to pay close attention and respond in a coordinated way. When it comes to acts that undermine China's interests, we will make firm and strong responses," its statement said.
Additional reporting by The Associated Press.