What other US President has authorized 'secret ops' to continue or prolong a war?

When Defense Secretary Ashton Carter announced Tuesday that the U.S. would begin "direct action" against Islamic State targets in Syria and Iraq, it sounded like a new mission for U.S. forces in a country where the president has repeatedly insisted Americans would not be engaged in combat operations. But America's special operations forces have been engaging in these kinds of missions for several months, particularly in the Kurdish-controlled provinces in northern Iraq. And the special operations forces have already built up an extensive infrastructure to support these activities. This casts doubt on the official Pentagon statements that last week’s raid was “a unique circumstance.” Since President Barack Obama authorized the first special operations teams to deploy to Iraq in the summer of 2014, the White House has provided few details on the mission and composition of the forces. The Pentagon today refers to the mission for the 3,500 U.S. service members as primarily "advise and assist," with an emphasis on training local forces. But the small and highly classified military footprint in northern Iraq shows the U.S. is more involved in the fight against the Islamic State.
http://www.bloombergview.com/articles/2015-10-28/new-u-s-combat-mission-in-iraq-is-not-new