The last several days have seen the once dormant debate—whether or not the U.S. should start supplying weapons to Ukraine—reignite.  The debate was revived by the release of a joint report by a group of ex-U.S. officials affiliated with three prominent American think tanks, which recommended that Washington urgently supply anti-tank missiles, counter-battery radars, and other military hardware to the Ukrainian armed forces so that the latter can deter Russia from escalating the conflict in Donbass.

One argument in favor of the West arming Ukraine is that additional weapons will deter Russia due to Vladimir Putin’s sensitivity to Russian casualties. There is no official data on Russian casualties in Ukraine, though one Russian NGO claims to have identified 260 Russian soldiers and volunteers who have been killed in action in eastern Ukraine.Reported attempts to conceal the cause and location of some of these deaths indicate that Russia’s leaders are sensitive to killings of active-duty Russian soldiers in the neighboring country.

Can the United States, European Union and Russia cooperate against the burgeoning common threat posed by the so-called Islamic State, even as their diplomats cross swords over the most recent escalation of fighting in Ukraine? The short answer is yes, but the path to cooperation will not be easy. The hard truth is that even when relations were good, counterterrorism cooperation was never as robust as many had hoped after 9/11. This was because of a fundamental conceptual gap about the nature of the terrorist threat.

For the United States, the threat comes in the guise of foreign radicals, determined to undermine the institutions of American society. That is the lesson Washington drew from 9/11 as it formulated its response. Al Qaeda in fact might have had a more limited goal of driving the United States from the Middle East, but Washington depicted the threat as one against the West's fundamental democratic values. For Russia, the terrorist threat is inextricably linked to separatism. That was the lesson Moscow drew from Chechnya as it formulated its counterterrorist policies. There were quite a few radical Islamists among the Chechen fighters even in the 1990s, but Moscow primarily saw them as a group determined to carve off territory for an independent secular state, not necessarily to destroy Russian society as such.

It is indisputable that the Ukraine crisis has dealt a serious blow to Russia's relations with core members of NATO. It would take many years for Moscow, Washington and Brussels to fully mend the fences even if the conflict in Ukraine were resolved tomorrow.

But as Russia's new military doctrine indicates, the Rubicon in NATO-Russian relations has not been crossed — at least not yet. While naming Russia's allies, the doctrine, which was published on Dec. 26, avoids designating either NATO as a whole or any of its specific members as adversaries.

Belfer Center hosts a conference on U.S.-Russian relations;   Pavel Zolotarev comments on U.S.-Russian counter-terrorism cooperation; William Tobey assesses Barack Obama’s policy in combating nuclear terrorism, and more.

The Ukrainian army has made significant gains against pro-Russian separatists in recent weeks, forcing the rebels to retreat to pockets around Donetsk and Luhansk. Victory seems to be within the Ukrainian soldiers’ grasp, but can it be attained and will it last?

With almost a week past the tragic crashing of a Malaysia Airlines passenger jet over eastern Ukraine, it is becoming clear that whatever initial hopes Western leaders might have had — that Russia’s Vladimir Putin can be shamed or coerced into unconditionally throwing the pro-Russian rebels under the bus — are futile. There is hope, however, that both the conflicting sides and their supporters will sit down to negotiate a sustainable resolution to the conflict which threatens the foundations of Europe’s already fragile system of collective security.

IPNT Participants Urge U.S and Russia to Continue Cooperating on Nuclear Security and Counter-Terrorism In Spite of Ukraine Crisis;  Matthew Bunn Highlights Insider Threats; Belfer Center Offers Policy Recommendations for Nuclear Security Summit;  and Elbe Group Calls for Continuation of Joint Actions on Preventing Nuclear Terrorism; and more.

In 2008, Kiev was actively pushing to integrate Ukraine into the West not only economically and politically, but also militarily. And yet Russia didn't intervene. So what's changed between now and then?