Today marks the 25th anniversary of the Beirut bombing. One of the quotes I always think of is, "The BLT [battalion Landing team] is gone!" It was. 1/8 lost almost all of its members. It's rare to find senior SNCO's or ltCol's and up that don't know someone who died there. It was one of the first big salvos in the War against fundamental Islam and we missed it. They, however, learned a valuable lesson - hurt the US enough and we go away. It's hurting us today because while we may not be leaving Iraq (for the time being anyway) they still believe we will so they don't stop. Perhaps if we held tough then they would just assume we don't bow to terrorists and stop trying to pin-prick us to death, casualty by casualty.
Some good stuff here on the USMC site.