This bill would sunset the 2001 Authorization for Use of Military Force (AUMF) three years after this legislation is enacted. The 2001 AUMF allowed for military action against those responsible for the terrorist attacks of September 11, 2001.
In practice, the 2001 AUMF has been used as justification for U.S. counter-terrorism operations around the world against groups like Al Qaeda and “affiliated forces” — although neither Al Qaeda nor any other group were specifically mentioned in the text of the 2001 resolution. The AUMF was signed by President George W. Bush on September 18, 2001 — and as of December 2015, the AUMF has been used to authorize force against the so-called Islamic State (ISIS) and other Islamic militant groups.