Russian President Vladimir Putin’s proposal to send U.N. peacekeepers to Ukraine received a tepid response from the West, but such a mission could very well be a first step in ending the conflict.

Putin’s proposed mandate for the force was exceedingly narrow, focused only on providing security for the unarmed Organization for Security and Co-operation in Europe (OSCE) monitoring mission that has been operating there since March 2014. The Russian proposal, which is now being discussed by the U.N. Security Council, calls for a U.N. force to be located only on the line of contact. Putin said publicly that the force should be deployed only after the sides disengage and withdraw heavy weaponry.

The idea of sending a U.N. peacekeeping operation to Donbas is not new. Indeed, it was first discussed by a small group of independent Russian and American experts on the Finnish island of Boisto in November of 2014. The Russian participants in this Track II exchange eventually publicized their proposals, but they were rejected by both Ukraine and key Western governments. Moscow also poured cold water on these ideas at the time. But good ideas don’t die. Rather, they reemerge when political conditions are ripe.

Press reports suggest that the Kremlin might now be open to a wider mandate but firm details remain hard to come by, prompting some observers to speculate that Putin was merely improvising or trying to upstage Ukrainian President Petro Poroshenko who has pushed similar ideas in recent years.

Reactions from Ukrainian and Western representatives have generally stressed their desire to explore what they see as the positive aspects of Putin’s proposal without boxing themselves in. It is easy to imagine that they will have plenty of reservations.

This isn’t the first time that Putin has floated this kind of idea. Back in April 2016, Putin mentioned during his televised call-in show with the Russian people that he supported Poroshenko’s proposal to deploy armed OSCE monitors along the line of contact. Now instead of arming members of the OSCE mission, Putin is suggesting that they be protected by a U.N. armed force.

The Minsk II ceasefire agreement signed in February 2015 made no provision for such a contingent. Roughly during this same timeframe, Poroshenko had called for the presence of U.N. peacekeeping forces in the Donbas, though he was talking about operating throughout the territory of the self-proclaimed Donetsk and Lugansk People’s Republics, not just along the line of contact.

The Minsk II process has been hopelessly stalled on nearly all issues for the past two and a half years. Even though the current level of violence is fairly low at the moment, the ceasefire is regularly violated, with both sides blaming each other. Some of the heavy weapons that were previously pulled back from the demarcation line have returned, and forces from both sides are still deployed in close proximity to each other, raising the likelihood that the conflict could intensify at short notice.

Moscow and its allies in Donbas routinely blame Kyiv for the impasse. They argue that the Ukrainian parliament balked at the political aspects of Minsk II, which called for changing the country’s constitution, passing a law on a special status for both Donetsk and Lugansk enclaves, conducting local elections, and instituting an amnesty. Ukraine’s internal political calamities and widespread popular fear of the Russian military threat have made it nearly impossible to implement Minsk II’s political provisions. There is widespread agreement in Kyiv that implementing Minsk II would be political suicide for the Poroshenko government.

For their part, Ukraine and the West have focused on Russia’s military involvement in the conflict. Moscow continues to categorically deny such claims. At the same time, Putin himself has pointed out that there were people “who are following the call of their hearts to fulfill their duty or are voluntarily taking part in hostilities, including in southeast Ukraine.” It’s clear that those fulfilling this duty aren’t doing so empty handed but with heavy weapons and abundant logistical support.

By ratcheting up economic sanctions and various forms of military and political pressure on Russia, the West is trying to get Moscow to end its military assistance to the Donetsk and Lugansk People’s Republics. Russia keeps insisting that it’s not part of the conflict and that all sanctions are illegitimate. The Kremlin claims that the West’s real goal is to bring Russia to its knees yet again and prevent it from defending its legitimate interests on the world stage. Russian officials state that the first order of business for the West should be to put pressure on Kyiv and force it keep up its end of the bargain. Obviously, there are fears in Moscow that any withdrawal of Russian military “volunteers” will lead to the quick collapse of the self-proclaimed republics and encourage Kyiv to try to solve the crisis via military means, just as it sought to do during the summer of 2014.

This is creating a vicious circle. The impasse on the Minsk agreements locks in the sanctions that both Russia and the West have imposed on each other. The deadlock also encourages NATO and Russia to continue a dangerous military build-up and more frequent military exercises. Risky encounters between warships and airplanes are also increasingly common. As a result, the world has ended up on the brink of a new nuclear and conventional arms race, all at a time when the civilized community of nations should be joining forces to defeat the common enemy of international Islamic terrorism.

Putin’s idea of deploying a U.N. contingent along the line of contact in Donbas could become the first step toward ending the crisis, but the idea needs to be expanded and refined. If OSCE observers were defended by U.N. peacekeepers, they would only be capable of defending themselves against small gangs. They would hardly be much use for dealing with artillery shells and incursions by combat troops along the line of contact, nor would they be able to ensure a complete and verifiable ceasefire or the withdrawal of heavy weapons. Such a force would not be powerful enough to prevent either side from restarting hostilities, and any troop contributors would be understandably worried about attacks on U.N. personnel.

A complete cessation of violence in southeastern Ukraine, the essential first condition of Minsk implementation, requires nothing less than a full-scale peacekeeping operation authorized by the U.N. Security Council. That mission would have to include troops from OSCE member countries equipped with armored vehicles, artillery, aviation, and unmanned aircraft. This contingent should have the right and capability to open fire in self-defense, to stop any violations of the ceasefire, and to ensure the pullback of heavy weaponry to agreed distances from the conflict zone.

Such an operation would have to be commanded by either the U.N. Security Council or the OSCE, not NATO or the European Union. The multilateral contingent would not be stationed throughout the Donetsk and Lugansk People’s Republics, but rather along the corridor between the two ceasefire lines created by the Minsk I and II agreements (specifically, the lines from which the parties were required to withdraw their heavy weapons). The peacekeeping mission will look a lot less like Kosovo in 1999 than the mission in Cyprus that began in 1974.

Make no mistake: This peacekeeping mission will not lead to the separatist territories returning to Kyiv’s control overnight, and — more controversially for Kyiv and the West — the deployment of a Russian contingent to this mission would be a prerequisite for attracting support from Moscow and the leaders of Donetsk and Lugansk. In Moscow, the reestablishment of Kyiv’s power over the breakaway territories is a political non-starter, and there are understandable fears that such a move would touch off a downward spiral of violence, revenge-killing, and score-settling. In this light, Russian memories of how NATO peacekeepers failed to prevent pogroms against the Serbs in Kosovo in March 2004 are also hard to dispel.

The cargo and personnel supplying the Russian contribution to the peacekeeping mission would be required to cross the interstate border with Russia under the observation of OSCE inspectors, pending the eventual return of Ukrainian border troops as stipulated under Minsk II. In theory, peacekeepers from other states, including the United States, might also participate, but this would be one of the most important and difficult parts of the mandate to negotiate. At the same, the official Russian military presence would be very different from what it is now: It could no longer be seen as actively supporting separatists but be aimed at preventing the resumption of combat operations by either side.

The carrot to secure Moscow’s political support has to be an agreed roadmap for sanctions relief that would begin as soon as the U.N. peacekeeping force becomes operative. (Admittedly, recent Congressional action to codify existing U.S. sanctions on Russia may complicate matters considerably for the Trump administration’s, given the current political atmosphere in Washington.)

Obviously, all these steps can only work if restoring peace is actually the parties’ predominant objective. This is an important reservation, since political forces pursuing other interests are involved in the conflict on all sides, and some of them may believe that they would benefit from an expansion of the fighting and of the confrontation between Russia and the West.

This should be a large-scale U.N. operation requiring political will on all sides, significant costs, and a serious organizational effort. It seems reasonable to expect that any idea along these lines will draw strong opposition, not least the charge that this approach could lead to a frozen conflict in eastern Ukraine.

Of course, there is nothing good about a frozen conflict, but it is worthwhile to assess the realistic rather than imaginary alternatives. For more than three and a half years, opposition to freezing the conflict has become a default position in both Ukrainian and Western policy circles. But Russia’s military escalation dominance is hard to overlook, and the Kremlin has demonstrated repeatedly that it is not prepared to let the separatists lose militarily.

If left to its own devices, the situation in eastern Ukraine is unlikely to improve, creating a real danger of further fighting and suffering by innocent civilians. The current military, political, and economic confrontation between Russia and the West could become permanent and lead to a new Cold War. In the worst-case scenario, there is a high enough probability of a return to large-scale combat operations in Ukraine and neighboring regions that directly involve Russian and, potentially, NATO forces. The effort and costs of a well-conceived peacekeeping operation pale in comparison with such grim prospects.

There is probably no other way to solve the Ukraine crisis, given current political realities. Three years of declarations, diplomacy, military moves, and sanctions have not brought stability let alone positive results. As the old saying goes, “However beautiful the strategy, you should occasionally look at the results.”

A U.N. peacekeeping operation would not imply renegotiating the Minsk II agreement. Instead, it would be a vehicle for allowing the parties to meet their obligations and move on to resolve broader problems of Russian-Ukrainian relations and Moscow’s deeply troubled relationship with the West.

What’s in it for Ukraine? Peace on its eastern borders would be guaranteed by an international military force operating under a U.N. mandate, which would put to rest any fears (real or imagined) of a Russian military invasion or further Russian support for separatist activities. That opens the door for Ukraine to focus its energies on long-overdue domestic reforms and integration with the European Union (Indeed, Cyprus marched down a similar path after 1974.) Eventually, economic, political, and humanitarian contacts between the two enclaves and the rest of Ukraine will hopefully be restored as envisioned under Minsk I and II. Ukraine’s sovereignty and territorial integrity would be restored (with the exception of Crimea, which is a separate subject and needs to to be postponed for the foreseeable future).

For its part, Russia would get sanctions relief and a guarantee against Ukrainian attempts to resolve the Donbas problem by force and would have to withdraw its “volunteers,” along with their weapons and equipment (as stipulated by Minsk II). The long-delayed implementation of the political aspects of Minsk II would provide Donestk and Lugansk with considerable autonomy and the right to develop economic and other types of cooperation with Russia. Eventually, restoration of centuries-old economic and humanitarian ties between Russia and Ukraine might become possible. It is conceivable that Moscow might be able to leverage such a settlement of the conflict to secure some form of assurance about Ukraine’s neutral status, but this heavily freighted issue probably needs to be deferred until much later on.

Members of the older generation can remember that it took decades and the herculean efforts of many people of different countries to end the Cold War. These people didn’t always like each other, and, in many cases they held profound mutual grievances. But they also had the right sense of political priorities and of the possible costs of failure. It is high time to start working along this line without delay before a new Cold War and arms race gain momentum for the decades ahead.

Alexei Arbatov is the head of the Center for International Security at the Institute at the Primakov National Research Institute of World Economy and International Relations in Moscow. Formerly, he was a member of the State Duma and deputy chairman of the Duma Defense Committee. This publication was produced as part of a Carnegie Moscow Center research project supported by the UK Foreign and Commonwealth Office.

Image: U.S. Army/Staff Sgt. Eric McDonough