Victor Davis Hanson has a provocative post at The Corner, on the patience of a government in a democracy at war:

…as is true in most long wars (cf. 1864 or 1918), armies seem not to be fully effective until they digest and learn from their horrific mistakes, and so enter a race to apply their wisdom before an exasperated public gives up.

In late summer 1864 the work of Sheridan and Sherman and the 1918 summer offensive uplifted public opinion enough to stick it out; in 1970-3 post-Tet, radical improvement in American tactics, weaponry, and know-how came too little too late to deflate the public sense of defeatism and doom.

And Michael Yon has thoughts on General Petraeus, and a letter from him to the troops, which may be viewed as crucial by historians.