Brookings (Washington, DC centrist policy think tank)
Carnegie Endowment for International Peace (According to their site, they are the oldest US and first global think tank.)
Hoover Institution (Conservative policy think tank at Stanford)
Hudson Institute (Conservative think tank)
IMEMO (Moscow Center for World Economics and International Affairs)
IISS (International Institute for Strategic Studies)
RAND (A nonpartisan, nonprofit institution providing research and analysis)
SIPRI (Stockholm International Peace Research Institute)