Top Pentagon officials, including Secretary of Defense Chuck Hagel and Joint Chiefs of Staff Chairman Gen. Martin Dempsey testified to the Senate Armed Services Committee today to brief them on the new war against ISIS in Iraq and Syria.

The two offered very few details on the plans for the war, though Gen. Dempsey conceded that the US ground troops in the country as advisers could end up being used in combat operations, despite repeated insistence this had been ruled out.

Dempsey presented the eventual attack on Mosul as one particular circumstance which could lead to the use of US ground troops in combat, saying they’d do “close combat advising,” while of course fighting themselves.

The one thing that was clear was that the war is going to be long, and both Dempsey and Hagel conceded that the current plans were unlikely to defeat ISIS in Syria. Hagel insisted that the current plans to train 5,000 Syrian rebels to fight ISIS would not be nearly enough to defeat ISIS.

In that regard, Sen. John McCain (R – AZ) was unusually the voice of reason, saying that the belief that the rebels would fight ISIS was a “fundamental misunderstanding” of their nature, and that their focus was on the Syrian government. The US-backed rebels have been allying with ISIS off and on, and recently signed a non-aggression pact.

Both of them tried to assure the Senate, though the news was decidedly not reassuring, that the strategy continues to be a work in progress and that regular adjustments would be made.