After nearly two decades of the "don't ask, don't tell" policy, the Defense Department will begin to review the ban on gays serving openly in the military next week. Lifting the ban will take several years, as it is something that "needs to be done very, very carefully," said Defense Secretary Robert Gates. A special investigation, expected to be announced Tuesday, will look into the best way to implement changes without damaging the morale of the troops. Military reactions to the repeal are unclear, and uncertainty about whether troops and leaders will tolerate open homosexuality poses a threat to the new plan. To ensure a smooth transition, President Obama will meet with Gates next week to discuss changes to the Clinton-era policy.