Born in California in 1945, Pillsbury was educated at Stanford University (B.A. in History with Honors in Social Thought) and Columbia University (M.A., Ph.D.). Major academic advisers to Pillsbury at Columbia were Zbigniew Brzezinski and Michel Oksenberg, who later played key roles in the Jimmy Carter administration on policy toward both China and Afghanistan. Pillsbury studied the art and practice of bureaucratic politics with Roger Hilsman, President John Kennedy's intelligence director at the State Department and the author of Politics Of Policy Making In Defense and Foreign Affairs. At Stanford, Pillsbury's academic mentor was Mark Mancall, author of two books on the influence of ancient traditions on Chinese foreign policy.
In 1969-1970 Pillsbury was the Assistant Political Affairs Officer at the United Nations. From 1971-72, he was a doctoral dissertation Fellow for the National Science Foundation in Taiwan, and in 1973-1977, Pillsbury was an analyst at the Social Science Department at RAND. In 1978, Pillsbury was a research fellow at the Center for Science and International Affairs at Harvard University.
During the Reagan administration, Dr. Pillsbury was the Assistant Under Secretary of Defense for Policy Planning and responsible for implementation of the program of covert aid known as the Reagan Doctrine. In 1975-76, while an analyst at the RAND Corporation, Pillsbury published articles in Foreign Policy and International Security recommending that the United States establish intelligence and military ties with China. The proposal, publicly commended by Ronald Reagan, Henry Kissinger, and James Schlesinger, later became US policy during the Carter and Reagan administrations.
Pillsbury served on the staff of four US Senate Committees from 1978-1984 and 1986-1991. As a staff member, Pillsbury drafted the Senate Labor Committee version of the legislation that enacted the US Institute of Peace in 1984. He also assisted in drafting the legislation to create the National Endowment for Democracy and the annual requirement for a DOD report on Chinese military power.
In 1992, under President George H. W. Bush, Pillsbury was Special Assistant for Asian Affairs in the Office of the Secretary of Defense, reporting to Andrew W. Marshall, Director of Net Assessment. Michael Pillsbury is a member of the Council on Foreign Relations and the International Institute for Strategic Studies.