Released Monday, the report comes as the U.S. top brass has declared a "stalemate" in its war against the Islamic State in its Iraq and Syria stronghold, while the 25,000-strong terrorist army of jihadis continues to grow via new foreign recruits and now operates in nearly 20 nations.
"Any coherent plan against the Islamic State must aim to eliminate, not merely degrade, its leadership and potential leadership," according to the report compiled by the RAND Corp., a nonpartisan think tank. "The coalition has successfully targeted numerous senior leaders, but the organization's focus on creating a deep bench of personnel means that attacking individual leaders will not destroy the group. Replacements will rise, and any damaging effect will be temporary."