Is Petraeus "the Man Most Responsible" for Fallon's Resignation?

When Secretary of Defense Robert Gates announced CentCom commander Adm. William Fallon’s resignation on Tuesday, he told the press that it was “a cumulative kind of thing,” not “any one issue” that led Fallon to leave his post. According to the New York Times’s Thom Shanker, “premature departure” at least partially “stemmed” from policy disagreements with Gen. David Petraeus, “a favorite of the White House“:

But there was no question that the admiral’s premature departure stemmed from what were perceived to be policy differences with the administration on Iran and Iraq, where his views competed with those of Gen. David H. Petraeus, the American commander in Iraq, who is a favorite of the White House.

Writing on the Washington Post’s website today, former intelligence analyst William Arkin posits that Petraeus is “the man most responsible for the departure of Fallon” because “the two were at odds on virtually every element of Iraq policy”:

Yesterday, I was hearing from Pentagon officials, high-ranking military officers and close observers of the building that the two were at odds on virtually every element of Iraq policy, which of course put Fallon on a collision course with the White House. In other words, Iran was the excuse but Iraq was the reason.

Arkin says Fallon believed “that the surge should [be] brought to a quick and successful conclusion.” But Petraeus had the White House, and “Fallon, despite his command and authority to set priorities and decide on what resources are needed, was frozen out.”

Most recently, the two top commanders disputed the length and purpose of the upcoming “pause” in troop withdrawals from Iraq this summer. Fallon thought it should be “temporary and brief” while Petraeus wants “to wait until as late as September to decide when to bring home more troops.”