The U.S. Army must be prepared for a wide range of future wars, Defense Secretary Robert Gates said Friday. But don’t count on fighting a land war in Asia—or the Middle East or Africa for that matter.

Mr. Gates said the U.S. will need swift-moving expeditionary and special-operation forces to respond to disasters, counter terrorism or conduct stability operations.

But a state-on-state land war with tanks and artillery? Don’t count on it.

Mr. Gates was skeptical that the U.S. Army or Marine Corps would be asked to fight a “high-end” war and said a “head-on clash of large mechanized land armies” was unlikely.

“Any future defense secretary who advises the president to send a big American land army into Asia, or into the Middle East or Africa should ‘have his head examined,’ as Gen. [Douglas] MacArthur so delicately put it,” Mr. Gates told an audience of West Point cadets Friday…