Neil "Cavguy" Smith (whose awesome visage can be found in this picture), a regular writer for Small Wars Journal, has written an excellent article regarding the application--and misapplication--of T.E. Lawrence's most favorite quote, which is quickly being relegated to the realm of cliche in modern counterinsurgency:
Do not try to do too much with your own hands. Better the Arabs do it tolerably than that you do it perfectly. It is their war, and you are to help them, not to win it for them. Actually, also, under the very odd conditions of Arabia, your practical work will not be as good as, perhaps, you think it is.
--T.E. Lawrence, The Arab Bulletin, 20 August 1917
Cavguy paints a wonderful vignette of how this quote is practically applied, and applied well. But not everyone has applied this quote to great effect. Bob Woodward's The War Within, an inside look at the decisions which led to the Troop Surge of 2007, begins with General George Casey refusing to ask for more troops, and insisting that US troops continue to play an advisory role, using the aforementioned quote from Lawrence...
...and misattributing it to Seven Pillars of Wisdom. Seriously, bad form.
But aside from the literary criticism, the quote was misapplied for a second reason. As the counterinsurgency manual notes, the key word in Lawrence's quote is tolerably. In 2006, the Iraqi Security Forces weren't performing tolerably--they were part of the problem. It meant that US troops had to step in to take the lead in 2006.
For more on the application and misapplicaton of Lawrence, check out this great article in Armed Forced Journal from Lt. Col. Robert Bateman.