"Know your enemy"

As suggested by immediately preceding post, I wanted to find source for the military maxim, "Know your enemy."

Turns out it's Sun Tzu's Art of War, and is expressed somewhat more verbosely:

If you know the enemy and know yourself, you need not fear the result of a hundred battles.

Why did I seek this maxim?

The good Gen Petraeus!

Gen David Petraeus told the BBC he thought Tehran had trained, equipped and funded insurgents who fired the barrage of mortars and rockets.
[Iran 'behind Green Zone attack' ]

All news stories related to the Green Zone attack acknowledge that it was carried out by core members - not splinter groups - of al Sadr's Mahdi Army.

Al Sadr is fiercely nationalistic - his Mahdi Army is not allied with Iran.

What evidence has Petraeus to support his belief that the attackers were "trained, equipped and funded" by Iran?

Short answer: none.

Why did he make this claim?

Short answer: it pleased his political masters.

Of the frequently identified Shiite militias, the one generally associated with Iran is the Badr Brigade, associated with the Supreme Islamic Iraqi Council (SIIC).
[I'd post Wikipedia links, but you all can look it up for yourselves... I'm tired.]

Petraeus's attribution of Iranian influence to al Sadr's Mahdi Army is not quite the gaffe that McCain's claim that Iran trained al Qaeda was, but it's close.

Both demonstrate a profound misunderstanding of the enemy.

["Outside agitators" are a favorite scapegoat of those in power. Somehow it is easier to blame them for problems than to admit that - in this particular case - Iraqi nationals object to our presence!
("Outside agitators" were a favorite scapegoat of Administrations during the Viet Nam debacle. Those in power simply could not admit that their own constituents could possibly object to U.S. policy - it had to be "the other".)]

And, in this particular case, blaming the Iranian bogey-man serves an additional political purpose: it helps set the stage for future action against Iran.

Okay, I'm ready to launch into my naked conspiracy theory again, so it's clear that I need to stop typing!

Stop the madness!