Six generals have spoken out against him. Is that a lot?

Two more retired generals stepped forward on Thursday and called for Donald Rumsfeld to resign, increasing the faction of outspoken officers to six. Rumsfeld brushed off the criticism: "Out of thousands and thousands of admirals and generals, if every time two or three people disagreed we changed the secretary of defense of the United States, it would be like a merry-go-round." How many retired admirals and generals are there?

It's hard to get good numbers, but the Explainer estimates that about 4,700 general officers are enjoying their retirement in the United States right now. (For a detailed look at the data and the Explainer's calculations, click here.) That means the six former generals who stepped forward to criticize Rumsfeld make up about one-tenth of 1 percent of the total community.

Retired generals pipe up all the time. In March, five of them wrote a letter to the Supreme Court asking that Justice Scalia recuse himself from the Hamdan case. In January, nine generals and three admirals banded together as the "Retired Generals Against Torture" and sent an open letter to the Senate judiciary committee. During campaign season, retired generals issue small-group political endorsements.

Bonus Explainer: The group of six that have been in the news includes four major generals, one lieutenant general, and one general. What's the difference? The plain old "general" has the highest rank—he wears four stars on his uniform. Three-star generals are called lieutenant generals, and two stars get you the title of major general. Brigadier generals wear only one star. (The Army, Air Force, and Marine Corps all use "general" titles. In the Navy, the top four positions are admiral, vice admiral, and two levels of rear admiral.)

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