As of spring 2007, surveys showed a majority of Americans in support of a timetable for withdrawal. While up to 70 percent of Americans in one survey favored withdrawal, most prefer to leave gradually over 12 months, and 60 percent say the U.S. has a moral obligation to the Iraqi people. In addition to voicing concerns over the human and financial costs of the war, supporters of withdrawal argue that the U.S. presence fosters ongoing violence by providing a target for al-Qaeda. It also allows Iraqi political leaders to avoid reaching a power-sharing agreement. The withdrawal will induce Iraq's neighbors to become more involved in quelling violence in the country and will relieve the strain on the U.S. military. The withdrawal debate has brought comparison of Iraq and Vietnam wars.