Probably the most specious cause to go to war led to the Spanish-American War. The USS Maine blew up due to unknown circumstances, and in the following weeks several things came together to stir the indignation of the American people. A letter from the Spanish ambassador to the King was published in the Hearst press, that painted a very unflattering picture of the President of the United States. Many were curious about "Granpas' experiences in the Civil War, and hawkishness reigned unchallenged.
Historians have largely concluded that the Maine's own boilers blew up. No one at the time ever asked how Hearst got the letter (mailed through the US Postal Service). Grandpa apparently never told his children about the absolute hgorror of combat, and would have had no experience with charging up a hill using a rifle using black powder against an enemy dug in using smokless powder.
Nonetheless, we ended up with Cuba, (which we granted independance to immediately) the Phillipines (which we did NOT grant independance to until the close of WWII), Guam, Wake, Puerto Rico, the Marianas Islands, and what is now the USVI.
Mistakes were made. Lives were lost. We came away with Spains former title as a World Power, and Spain never had much else to play on the world's stage.
Lessons learned: 1) even if you try to plan ahead, you can STILL send troops to Cuba and the Phillipines with extra blankets!
2)Even if your motives are somewhat questionable, your cause all a mistake, and your execution sloppy, if you press your attack home, and force your enemy to surrender, you can gain the respect of those who would otherwise use and abuse you.
Our current conflict is not without debate, it can be easily argued that we debated the issue too long before acting. Our motives, while many are contemptuously scorned, were in good faith, and if our President acted on faulty intelligence, so did many of those who now scorn him (Clinton, Dashcle, Gore, Kerry). While not as prepared as we COULD have been, our preparations were MUCH more complete than we have seen in past conflicts, woolen uniforms and extra blankets to the tropics; gathering planes togetrher in the middle of Hickam and Wheeler Airfields; Going to "whup the Rebs" in Manassas (First Battle of Bull Run; ect, ect, ect) Not being ready to defeat the enemy as quickly as we did, and not having enough troops on the ground to immediatly restore order are pretty arcane details compared to some of historys lessons. If we pull out of Iraq at this time, the situation will deteriorate, into the EXACT same mess as the Russians left in Afghanistan. If we see this through, them those who despise us will again realize that it is safe to do so, from afar. But we are STILL a force to be reckoned with when attacked, and we WILL enforce the terms of surrender, cease-fire, or whatever form the following peace may take. To quit at this point only invites the hyenas to circle closer!