He is also Senior Counsellor to the Long Term Strategy Group based in Washington D. C., a defense consulting firm.
As a postdoctoral fellow at Harvard he worked with Sam Huntington to create the Olin institute for Strategic Studies.
The book explains the strength and weakness of the Indian army during the Mughal, British, and post independent eras.
Parallel to his career in academia, he worked for Herman Kahn at the Hudson Institute (1973 and 1974) and served in the United States government from 1981 to 1990.
He was the Director of Political-Military Affairs on the staff of the National Security Council 1984-1985 where he was the author of NSDD 166, the strategy document for the American operations in Afghanistan.
[1] Shortly after the September 11 attacks, Rosen signed an open letter from the Project for the New American Century to President George W. Bush[2] that advocated war in Afghanistan and "a large increase in defense spending."
Rosen also signed the PNAC's Statement of Principles and its controversial 90-page report entitled Rebuilding America's Defenses: Strategies, Forces and Resources for a New Century (2000), advocating the redeployment of U.S. troops in permanent bases in strategic locations throughout the world where they can be ready to act to protect U.S. interests abroad.
[3] In 2007, Rosen was named as a member of foreign policy advisory team of Republican Party presidential candidate Rudy Giuliani.
[4][5] Rosen holds the view that U.S. military supremacy is not guaranteed into the future, remarking on it that, "we [Americans] have grown up and become accustomed to a world in which we can exercise force majeure and we just can’t do that.