From 1978 to 1982, he served as Associate Director of the National Security Strategies Program at think tank RAND Corporation, conducting and supervising research and analysis of classified material under contract with the Pentagon and the US State Department.
[3] In 1982, Rosen left RAND to join AIPAC, where he served until 2005 as Director of Foreign Policy Issues and was particularly involved in communication with the executive branch including the State Department and the National Security Council.
The New York Times said, "Mr. Rosen, AIPAC's director of foreign policy issues, is ... one of the group's most influential employees, with wide-ranging contacts within the Bush administration and overseas.
[8] The Nation said Rosen is "a brilliant and, some say, ruthless bureaucratic infighter at the country's premiere Mideast lobbying group, who was emboldened by his long relationships with figures in and around the Bush Administration and the Washington scene to behave almost as an unofficial diplomatic entity in his own right" (July 14, 2005).
Columnist William Safire and defense correspondent Drew Middleton credited one of Rosen's reports with helping to launch the U.S.–Israeli dialogue that resulted in the Strategic Cooperation Agreement during early the Ronald Reagan administration.
An early success came in 1983, when he helped lobby for a strategic cooperation agreement between Israel and the United States, which was signed over the objections of Caspar Weinberger, the Secretary of Defense, and which led to a new level of intelligence sharing and military sales.
Rosen and his codefendant in the AIPAC/Franklin case Keith Weissman were among the first to advocate a strategy of graduated American economic sanctions for leverage against Iran's alleged involvement in sponsoring terrorism and its purported acquisition of nuclear weapons capabilities.
The Executive Orders and ILSA (later the Iran Sanctions Act) were the foundation of a Bush Administration effort to get multilateral cooperation for stepped up economic pressure to end the Iranian uranium enrichment program.
Rosen was an ardent proponent of the view that U.S. recognition of and relations with Palestinian organizations should be conditioned on their renunciation of terror and violence, their willingness to make peace and their compliance with signed agreements.
[3] At the height of the failed 1990s peace process, he was criticized by followers of Israel's leading dove, Yossi Beilin, for expressing doubts that the Palestinians would honor their commitments.
The same day, Federal Bureau of Investigation (FBI) agents, accompanied by media camera crews, raided AIPAC offices with a warrant to inspect the paper and electronic files of Steven Rosen.
[13] The indictment of Rosen and Weissman, filed in Alexandria, Virginia on August 4, 2005, alleges that:[3][13] "Between in or about April 1999 and continuing until on or about August 27, 2004, in the Eastern District of Virginia and elsewhere, defendants Lawrence Anthony Franklin, Steven J. Rosen, and Keith Weissman did unlawfully, knowingly and willfully conspire, confederate and agree together and with others, known and unknown to the Grand Jury, to commit the following offenses against the United States: The indictment stated:[14] On May 1, 2009 prosecutors announced they would ask the judge to dismiss the cases against Rosen and Weissman because of "the diminished likelihood the government will prevail at trial under the additional intent requirements imposed by the court and the inevitable disclosure of classified information that would occur at any trial.
"[15] On November 3, 2008, the Jewish Telegraphic Agency reported that Rosen was working for the Middle East Forum (MEF), a think tank directed by scholar Daniel Pipes.