WASHINGTON — For years, the Joint Special Operations Command, known throughout the Pentagon as JSOC, has provided standing forces of American commandos to track down terrorist leaders overseas. Now, in announcing that it is deploying a small team of special operators to Iraq to carry out raids against high-value Islamic State leaders in Iraq and Syria, the Pentagon is turning to its elite team of manhunters once again.

The defense secretary, Ashton B. Carter, did not use the acronym JSOC when he disclosed his plans before a House hearing on Tuesday; instead, he referred to a “specialized expeditionary targeting force.” But the commandos — Defense Department officials said they would number at least 100, including support personnel — will have a mission similar to (but smaller than) the one they carried out in tandem with President George W. Bush’s surge of American troops in Iraq in 2007. There, commandos conducted a series of high-tempo, nightly raids to capture or kill fighters from Al Qaeda and other former Baathist groups in Iraq.

Now, the new enemy is the Islamic State, which includes members of the old enemy who were not killed last time. Many officials said privately that they viewed the new deployment as only the beginning of what could be a phased intensification of the war effort in Iraq and Syria.

The newly deployed commandos “will conduct raids,” said Col. Steven H. Warren, spokesman for the American-led coalition against the Islamic State in Baghdad. “Absolutely no question about that,” Colonel Warren said. “Their presence will focus on high-value individuals, high-value targets.”