New satellite imagery has emerged showing what appears to be the first signs of significant construction of surface structures at North Korea’s Punggye-ri nuclear test site since its apparent implosion four years ago. The Planet Labs shots from Feb. 18 and March 4, analyzed by Jeffrey Lewis and his team at the James Martin Center for Nonproliferation Studies, may point to “preliminary” activities at the nuclear site.

If there’s any good news with the resumption of construction at the site, it’s that North Korea probably is not secretly constructing a new nuclear test site to carry