Nunn-Lugar in Russia, we hardly knew ye.

Well, that’s not entirely true – in fact, we knew ye fairly well. For more than twenty years, under the auspices of the Nunn-Lugar Cooperative Threat Reduction (CTR) program, the United States partnered with Russia to secure, protect, and dismantle weapons of mass destruction throughout the former Soviet Union. However, this past Sunday saw the expiration of the US-Russian “umbrella agreement” that made this program possible.

In its stead the two sides have negotiated a successor agreement that will discontinue some US-Russian WMD cooperative efforts while allowing others to continue.

CTR in Russia arose in the aftermath of the Soviet collapse in the early 1990s, when Russia inherited most of the former Soviet Union’s massive nuclear weapons complex. However, in this chaotic period, the Russian government lacked the funds to maintain the security of its nuclear facilities, materials, and weapons. What resulted was the stuff of WMD security nightmares – accounts of this period reveal stories of vital security upgrades being ignored, salaries for personnel going unpaid, and “sheds [of] world-ending supplies of [highly-enriched uranium] protected by padlock only.”

Enter CTR. Founded in 1991, through legislation sponsored by Senators Sam Nunn and Richard Lugar, CTR saw significant success in securing and dismantling excess Russian nuclear weapons. US-Russian cooperation resulted in the elimination of more than 7,600 warheads, 900 ICBMs, and 680 SLBMs from the Russian nuclear complex, as well as the implementation of important security upgrades at more than two dozen nuclear weapons facilities.

Since its inception, CTR has expanded beyond the realm of former Soviet states, broadening its mandate in order to to provide assistance to governments in Asia, North Africa, and the Middle East. Meanwhile, under the terms of legislation proposed by Senator Jeanne Shaheen (D-NH) in May 2013, the program’s presence in the latter two regions would be stepped up significantly, in an effort to prevent WMD from falling into the hands of non-state actors.

Why, then, did the US and Russia allow the aforementioned “umbrella agreement” to expire? In October 2012, the Russian government announced that it would not seek to renew the pact, citing fundamental disagreements with the agreement extension proposed by US negotiators.

Analysts have highlighted a variety of potential reasons for the Russian withdrawal. Several have pointed to the embarrassment felt by many Russian officials about having to rely on a foreign power for domestic security concerns, with the Stimson Center’s Brian Finlay describing Nunn-Lugar as “an enduring political embarrassment for Moscow.” More specifically, the liability provisions of Nunn-Lugar, under which US representatives and contractors were essentially protected from all legal liability for CTR-related incidents, were a constant sticking point for the Russian government.

Despite the end of Nunn-Lugar, US-Russia WMD-security cooperation will continue, albeit in a truncated form. This past Monday, on the sidelines of the G-8 summit, President Obama and Russian President Vladimir Putin reached an agreement to continue the US-Russia partnership under a new framework, which our friends over at Arms Control Wonk have cleverly dubbed “non-Lugar.” Within the context of this new arrangement, the US will no longer be assisting Russian officials with the dismantlement of missiles, bombers, and chemical weapons, but, according to a senior US official, will be able to continue most of its nuclear security-related work without issue under the 2003 “Framework Agreement on a Multilateral Nuclear Environmental Programme in the Russian Federation,” and a related protocol signed on June 14, 2013. Former senators Nunn and Lugar have come out in support for this new arrangement, though other analysts have expressed a bit more skepticism.

The end of US assistance in dismantling the Russian chemical weapons arsenal is particularly troubling, given that Russia is estimated to have thousands of tons of chemical agent still awaiting destruction. With the end of Nunn-Lugar, Russia will be left with the responsibility of ensuring that this important arms control mission is fulfilled. As David E. Hoffman pointed out in an October 2012 post for Foreign Policy, the Russian government, buoyed by a resurgent economy, certainly has the means to carry out this task – the more salient question is whether it will actually do so.

Such concerns about Russia’s commitment to Nunn-Lugar’s objectives are nothing new. Back in 2006, in a feature for The Atlantic, William Langewiesche detailed how many National Nuclear Safety Administration (NNSA) technicians, sent abroad to help their Russian counterparts enhance the security of Russian nuclear facilities, questioned Moscow’s commitment to nuclear security, and expressed concerns that the CTR-funded upgrades would “slip into disrepair” upon the termination of US funding.

Though the US will apparently still have a hand in ensuring the security of Russia’s nuclear materials, its involvement in other aspects of the Nunn-Lugar agenda will be more limited. What this means for Russia’s WMD security remains to be seen.