The authors, respectively the president of and a senior fellow based at the Council on Foreign Relations, write:

• The Russian military’s numerical superiority likely gives it the ability to counter Ukraine’s greater operational skill and morale, as well as its access to Western support. Accordingly, the most likely outcome of the conflict is not a complete Ukrainian victory but a bloody stalemate.
•  But with Moscow and Kyiv both vowing to keep up the fight, conditions are not yet ripe for a negotiated settlement. Russia seems determined to occupy a larger chunk of the Donbas. Ukraine appears to be preparing an assault to break the land bridge between the Donbas and Crimea.
• The West needs an approach that recognizes these realities without sacrificing its principles. The best path forward is a sequenced two-pronged strategy aimed at first bolstering Ukraine’s military capability and then, when the fighting season winds down late this year, ushering Moscow and Kyiv from the battlefield to the negotiating table.
• It is difficult to see what Russia would gain from escalation. Expanding the war by attacking a NATO member would not be in Russia’s interests. A nuclear attack would likely prompt NATO to enter the war directly and decimate Russian positions throughout Ukraine.....It is thus time for the West to stop deterring itself and start giving Ukraine the tanks, long-range missiles, and other weapons it needs to wrest back control of more of its territory in the coming months.
• Yet for all the good that greater Western military help would do, it is unlikely to change the fundamental reality that this war is headed for stalemate. ... if Moscow’s military position were to become precarious, it is quite possible that China would provide arms to Russia.
• Later this year, a stalemate is likely to emerge along a new line of contact. When that happens, an obvious question will arise: What next?
•  Ukraine should not risk destroying itself in pursuit of goals that are likely out of reach.
• Come the end of this fighting season, the United States and Europe will also have good reason to abandon their stated policy of supporting Ukraine for ‘as long as it takes,’ as U.S. President Joe Biden has put it. Maintaining Ukraine’s existence as a sovereign and secure democracy is a priority, but achieving that goal does not require the country to recover full control of Crimea and the Donbas in the near term. Nor should the West worry that pushing for a cease-fire before Kyiv reclaims all its territory will cause the rules-based international order to crumble.
• The reality is that continued large-scale support of Kyiv carries broader strategic risks.
• The war is eroding the West’s military readiness and depleting its weapons stockpiles;
• United States must prepare for potential military action in Asia (to deter or respond to any Chinese move against Taiwan) and in the Middle East (against Iran or terrorist networks).
• The war is imposing high costs on the global economy, as well. 
• Against this backdrop, neither Ukraine nor its NATO supporters can take Western unity for granted.
• The United States and its partners need to begin formulating a diplomatic endgame now.
• Ukraine’s Western supporters would propose a cease-fire as Ukraine’s coming offensive reaches its limits.
• Ideally, both Ukraine and Russia would pull back their troops and heavy weapons from the new line of contact, effectively creating a demilitarized zone.
• A neutral organizationwould send in observers to monitor and enforce the cease-fire and pullback. The West should approach other influential countries, including China and India, to support the cease-fire proposal.
• Assuming a cease-fire holds, peace talks should follow. Such talks should occur along two parallel tracks.
•  On one track would be direct talks between Ukraine and Russia, facilitated by international mediators, on the terms of peace.
• On the second track, NATO allies would start a strategic dialogue with Russia on arms control and the broader European security architecture.
• Provided that Ukraine makes battlefield gains this summer, it is at least plausible that Putin would view a cease-fire and peace plan as a face-saving off-ramp. To make this approach even more enticing, the West could also offer some limited relief from sanctions in return for Russia’s willingness to abide by a cease-fire, agree to a demilitarized zone, and participate meaningfully in peace talks.
• Kyiv may ultimately find much to like in the plan. Even though the end of fighting would freeze in place a new line of contact between Russia and Ukraine, Kyiv would not be asked or pressured to give up the goal of taking back all of its land, including Crimea and the Donbas.
• Even if a cease-fire held and a diplomatic process got underway, NATO countries should continue to arm Ukraine, removing any doubts in Kyiv that its compliance with a diplomatic roadmap would mean the end of military support.
• As another incentive to Ukraine, the West should offer it a formalized security pact. Although NATO is unlikely to offer membership to Ukraine—a consensus within the alliance appears out of reach for now—a subset of NATO members, including the United States, could conclude a security agreement with Ukraine that pledges it adequate means of self-defense.
• Alongside this security pact, the EU should craft a long-term economic support pact
• For over a year, the West has allowed Ukraine to define success and set the war aims of the West. This policy, regardless of whether it made sense at the outset of the war, has now run its course. It is unwise, because Ukraine’s goals are coming into conflict with other Western interests.
• As a global power, the United States must acknowledge that a maximal definition of the interests at stake in the war has produced a policy that increasingly conflicts with other U.S. priorities.

Read the full article at Foreign Affairs.

The opinions expressed herein are solely those of the author. Photo obtained from Flickr and shared under a Creative Commons license.