Muslim cleric sanctions beheading Americans

Thanks to MEMRI, we know that Muslim clerics are not without heart.

Sheikh Dr. Yousef Al-Qaradhawi, a leader of the Muslim Brotherhood movement issued a fatwa and told Muslims: "The abduction and killing of Americans in Iraq is a [religious] obligation so as to cause them to leave Iraq immediately. The mutilation of corpses [however] is forbidden in Islam."

As MEMRI reports, many clerics are disputing this judgment. One opponent argues: "Iraq has its [own] senior religious authorities who understand the country and its residents… The Fatwas that are being issued by clerics outside of Iraq's borders are not based on an accurate understanding of the state of affairs in the country."

My question is: shouldn't their judgment be basis, not on where they are, but based on the Qur'an or Shari'a?

Is it really that hard to figure out that mutilating a corpse is a sick and twisted thing to do, whether he is an enemy combatant or not?

The Prophet conquered his enemy with sword, and his methods are still being employed with glee 14 centuries later.