The coalition bargain behind Eisenhower's command

Why was Eisenhower selected over Roger Keyes for supreme command?

American resources made an American supreme commander politically necessary, while British officers led several major component commands.

Eisenhower's appointment reflected a coalition bargain rather than a simple ranking of individual commanders. The United States supplied a growing share of the forces and resources, making an American supreme commander politically important. British officers could then hold major component commands for land, air, and sea operations beneath him. The arrangement helped keep the United States fully committed to Europe while distributing authority across the alliance.