Nearly two months into Vladimir Putin's brutal assault on Ukraine, the Biden administration and its European allies have begun planning for a far different world, in which they no longer try to coexist and cooperate with Russia but actively seek to isolate and weaken it as a matter of long-term strategy.

At NATO and the European Union, and at the State Department, the Pentagon and allied ministries, blueprints are being drawn up to enshrine new policies across virtually every aspect of the West's posture toward Moscow, from defense and finance to trade and international diplomacy.

Outrage is most immediately directed at Putin himself, who President Biden said last month "can't remain in power." While "we don't say regime change," said a senior E.U. diplomat, "it is difficult to imagine a stable scenario with Putin acting the way he is."

But the nascent new strategy goes far beyond the Kremlin leader, as planners are continuing to revise seminal documents that are to be presented in the coming months. Biden's first National Security Strategy, legally required last year but still uncompleted, is likely to be significantly altered from initial expectations it would concentrate almost exclusively on China and domestic renewal. The Pentagon's new National Defense Strategy, sent last month in classified form to Congress, prioritizes what a brief Pentagon summary called "the Russia challenge in Europe," as well as the China threat.

NATO's first Strategic Concept document since 2010, when it sought a "true strategic partnership" with Russia, will be unveiled at the alliance summit in June. "Meaningful dialogue, as we strived for before, is not an option for Russia," NATO Secretary General Jens Stoltenberg said at a news conference early this month.

The European Union has drawn up plans to cut its heavy dependency on Russian gas by two-thirds by the end of this year, and end all fossil fuel imports from Russia before 2030. "It is not so much about sanctions, but it is about articulating a path to zero, making sure that we become independent of Russian gas and oil," Dutch Foreign Minister Wopke Hoekstra said in a forum Thursday at the Center for Strategic and International Studies in Washington.

"For some, that will be a trajectory of months. For others, it might be years. But the Netherlands and other countries are dead serious about this," Hoekstra said. "Never again the same mistake."

Allies have announced major defense budget increases stretching far into the future. Finland and Sweden are expected to apply for NATO membership ahead of the June summit in Madrid, a significant shift in the balance of European security that would also sharply increase the alliance's military presence near Russia.

A week ago, Biden signed bills ending normal trade relations with Russia and codifying his U.S. ban on Russian oil imports. Last week, the United Nations General Assembly voted to suspend Russia's membership from the U.N. Human Rights Council, and a long-simmering movement to revise the membership and powers of the Security Council, where Russia freely uses its veto power, gained new impetus.

Few Western leaders are willing to venture a guess as to when, and how, the Ukraine crisis will play out. Many of the proposed changes "can't be fully decided until we know how this conflict ends," said Alexander Vershbow, a former U.S. ambassador to Russia, senior Pentagon official and deputy NATO secretary general. "Does it end?" Or does it drag on with an uneasy cease-fire, with "no war, no peace, for several years?"

But the long-term strategy is being drawn up even as the allies address the immediate crisis with escalating sanctions against Moscow, weapons aid to Ukraine, and the deployment of tens of thousands of their own troops to NATO's eastern border. Many of those measures and more are now expected to stay permanently in place, according to public leader statements and conversations with eight senior U.S. and foreign officials, some of whom spoke on the condition of anonymity to discuss closed-door planning.

"At the end of the day, what we want to see is a free and independent Ukraine, a weakened and isolated Russia and a stronger, more unified, more determined West," Biden national security adviser Jake Sullivan said last Sunday on NBC's "Meet the Press." "We believe that all three of those objectives are in sight."

Some have questioned both the wisdom of the plans and the staying power of the West, advising against a return to the "containment" policy that governed relations with the Soviet Union. Others have said the Ukraine crisis, and its profound effect on Europe, offer an opportunity for the United States to withdraw from at least some of its expensive, self-assumed responsibilities to defend the free world.

"If anything," historian Stephen Wertheim argued this month in Foreign Affairs magazine, "the war has strengthened the case for strategic discipline, by offering a chance to encourage Europe to balance against Russia while the United States concentrates on security in Asia and renewal at home."

Not everyone favors the long-term isolation of Moscow. In France, where President Emmanuel Macron is locked in a surprisingly close reelection race with the surging candidacy of Marine Le Pen, she has called for reconciliation between NATO and Russia and has reiterated a pledge to pull France out of the alliance's integrated command. And there are voices in Germany in favor of keeping the door open to dialogue with the Kremlin to facilitate an eventual rapprochement.

In the United States, the issue is one of the few in which Biden has strong bipartisan support. Backing for a tough line against Russia appears also to have subdued Republican disdain for NATO, a hallmark of the Trump administration, as alliance members from Washington to Russia's western border insist that the need for, and the reality of, a common stand is higher than ever before.

But if the immediacy of Ukraine dissipates, along with daily images of new horrors there, disagreements inevitably will arise over increased defense spending, the need to engage with Russia on issues such as nonproliferation, charges that attention is being pulled away from China, and disruptions of trade that bring rising prices at home that disrupt the president's domestic agenda.

"We must commit now to be in this fight for the long haul," Biden said during a visit to Warsaw last month, outlining the fight as one between democracy and autocracy. "We must remain unified today and tomorrow and the day after and for the years and decades to come. It will not be easy. There will be costs."

The last major overhaul of relations with Russia, guiding hopes after the collapse of the Soviet Union, came in 1997, when NATO leaders and Moscow approved the "Founding Act on Mutual Relations, Cooperation and Security." Reflecting "the changing security environment in Europe . . . in which the confrontation of the Cold War has been replaced with the promise of closer cooperation among former adversaries," it said they would act together to build "a lasting and inclusive peace in the Euro-Atlantic Area."

As it sought to tie Russia to interdependency, the Founding Act included specific commitments to respect states' sovereignty, peacefully settle disputes, and, on NATO's part, an intention to avoid any additional permanent stationing of "substantial combat forces" on Russia's borders. It also specifically said it was not intended to "delay, limit or dilute NATO's opening for the accession of new members."

In subsequent years, those commitments were often tested, most recently before the current crisis by Russian's 2014 invasion of parts of eastern Ukraine and annexation of Crimea, and resulting Western sanctions. But even after those events, Europe and the United States eased back into a relationship with Russia, either out of economic imperatives, as with Europe's energy imports, or out of desire, as when former president Donald Trump bragged about his deep bond with Putin.

But at an emergency NATO summit last month, "leaders agreed to reset our deterrence and defense for the long term," Stoltenberg said. "To face a new security reality" with substantially more forces in the east, more jets in the skies and more ships at sea. Russia has "walked away" from the Founding Act, he said later. "That doesn't exist any more."

A senior European official said that "the one lesson we take away from a Russian aggression that many thought could not be possible, is that here is a country that is ready to do something that no security guarantee or even plausible expectation [can ensure] that it can't happen again."

"We thought interdependence, connectiveness, would be conducive to stability because we had correlating interests. Now, we've seen this is not the case. Russia was highly connected with Europe, a globalized country." the official said. "Interdependence, we've now seen, can entail severe risks, if a country is ruthless enough. . . . We have to adapt to a situation that is absolutely new."

Several European policymakers said their current calculations are shaped by two major factors. The first is the expectation that any truce in Ukraine is likely to be temporary. Even if Putin agrees to lay down arms for the moment, many Europeans believe he will seek to regroup, rebuild the Russian military and attack again once he feels ready.

The second is a deep horror at the Russian military's atrocities against civilians that have come to light since its forces pulled back toward eastern Ukraine in the past two weeks. Many believe Putin himself may need to face war crimes charges in front of international tribunals.

The combination means many Europeans feel their continent will be unstable and insecure so long as Putin is in the Kremlin. And if they are not yet willing to embrace an active effort to oust his regime, support is growing there, as well as in the United States, to permanently cut off his country.

"There is growing realization that this is a long-term situation and that a strategy of containment, a strategy of defense, is forming," Latvian Foreign Minister Edgars Rinkevics said in an interview. "Support Ukraine as much as you can, sanction Russia as much as you can, do as much as you can do to reduce dependence on Russia however you can and finally, yes, put more emphasis on military defense."

Rinkevics was among the E.U. foreign ministers who had breakfast in Luxembourg this week with the chief prosecutor of the International Criminal Court to discuss war crimes.

"When it comes to the investigation of all the war crimes, it cannot stop at the field commander, and in Russia, the ultimate commander in chief is the president of the Russian Federation," Rinkevics said. "The feeling after Bucha," the Kyiv suburb where withdrawing Russian troops left scores of dead civilians in the streets, some apparently tortured and executed, "is that it will be very difficult to speak with Putin or anyone in the Russian government without remembering what happened."

Apparently strong backing for the war among Russians has also caused a recalculation among allied policymakers about a long-standing effort to draw a distinction between the country's population and its leadership, said Lithuanian Vice Defense Minister Margiris Abukevicius. Russians appear to have the leaders they want, he said - another reason to dig in and prepare for a long standoff.

"There is collective responsibility," Abukevicius said. "At the beginning, we were saying 'Putin's war.' Now, we are more and more saying 'Russia's war.'"