The Supreme Court's ruling last week in Hamdan that military commissions erected at Guantánamo are inconsistent with our military law and the Geneva Conventions has already prompted fierce-and flawed-debate. One key question, especially relevant in next week's Judiciary Committee hearings on Hamdan, is whether and how the Geneva Conventions apply to military commissions. The many factually and legally incorrect assertions clogging the air make it worth stepping back to understand what Geneva does, and why it matters for our success against the terrorist threat.

Death is typically a moment of truth. But the occasion of three suicides at the Guantánamo Bay-where almost 500 men and boys have been held without trial for up to four years now-have only proved how poorly the Administration grasps the facts of today's terrorism challenge. And it only showed how deeply ineffectual and counterproductive U.S. counter-terrorism policy becomes when based on flawed assumptions.