'...the United States should only take on wars that could sustain popular support and not those that threatened to be indecisive.'
The withdrawal was important, because it gave the impression that America was vulnerable to terrorism and that if casualties were high enough they could be coerced into abandoning hazardous overseas commitments. It prompted Caspar Weinberger, Reagan's secretary of defence, to state that the United States should only take on wars that could sustain popular support and not those that threatened to be indecisive. This had already been taken by many to be the 'lesson' of Vietnam, when the US was seen to have retired exhausted from an apparently futile conflict, even though they had not been defeated in battle.
The killings led to a call from the UN Security Council for the arrest of those responsible, and the Rangers were sent to achieve this. When they went to find Aidid at the Olympic Hotel in Mogadishu, they got ambushed instead by Somalis (including women and children) armed with automatic weapons and rocket-propelled grenades. Some of the most vicious fighting occurred during the attempt to save a US helicopter, Black Hawk, brought down in the city's back streets.
The battle lasted for 17 hours and left 18 US soldiers killed and 84 wounded, with many Somalis also dead (some estimates put the number as high as 1,000). Almost immediately after the battle, President Clinton decided to abandon the hunt for Aidid and set a date for the US withdrawal from Somalia.