you can't wait until things are perfect before you act, otherwise you'll never act at all. One name for this is "analysis paralysis", where people get so hung up on analyzing a situation that they're unable to make a decision or take any actions.

Should we have waited 2 years before acting in Afghanistan after 9/11? After all, we didn't have everything we needed when the fighting started. What would've happened in the meantime? Those training camps would've still been turning out thousands of new terrorists every year. The Taliban would've still been making life in that country a living hell. They could've also used the time to beefen their defenses, meaning dislodging them all the more difficult. The same applies to Iraq. Had we waited another 2 years, what would've happened?

If you can't see the parallels between GWII and previous wars, then perhaps you should read some good military history books. We went into WWI without a single combat ready aircraft in our inventory, without enough artillery, machine guns, or ships. We went into WWII with shortages of just about everything. Even as late as D-Day* (a very carefully planned operation), there were still shortages and massive mistakes. The troops improvised. We went into Korea without enough of anything and got our butts kicked all the way down the penensula until the Inchon landings. In Vietnam, the very boots rotted off of soldiers' feet, the weapons jammed in the harsh jungle conditions, and we actually ran very low on aerial bombs at one point. I can list many other examples from later conflicts, too.

The point is that you can't always anticipate all of the possible needs or all of the possible enemy actions. The insurgents have been very innovative in adapting their tactics, especially in regard to IEDs. We're in the process of compensating. Such is the nature of war. Those who have blind faith in government's ability to plan everything seem to have a hard time coming to grips with the messy real world, especially in wartime.