In honor of the 50th anniversary of the Limited Test Ban Treaty (LTBT), Ploughshares Fund is dedicating a series of blogs on how the treaty influences nuclear disarmament today. The LTBT was the first concrete step toward the elimination of nuclear testing. Under the LTBT, U.S. research and development on nuclear weapons is still permitted in the national laboratories. One of the groups working to convert this weapons development actvity into socially beneficial research is our grantee, Tri-Valley CAREs (Communities Against a Radioactive Environment). We asked Tri-Valley CAREs Executive Director Marylia Kelley for her insights on how the LTBT impacts her work and what more can be done to stop nuclear testing.