Outgoing BAE Systems Inc. CEO Linda Hudson was also named to the think tank’s board on Monday.
The additions will add to the clout of the centrist defense think tank, which was founded in 2007.
Former Secretary of State Madeleine Albright, who joined the CNAS board in 2007, and former Defense Secretary William Perry, the think tank’s founding chairman, were named directors emeriti.
Allen, who retired from the military in 2013, commanded U.S. forces in Afghanistan from 2011 to 2013.
Lieberman was a Democrat-turned-Independent in the Senate who was hawkish on national security issues, allied with Sens. John McCain (R-Ariz.) and Lindsey Graham (R-S.C.) as the “three amigos.”
Hudson, who plans to step down from her post at BAE Systems in 2014, was the first woman ever to head a major defense contractor.