As President Barack Obama and Russian President Dmitry Medvedev ended a public conference in South Korea (a nation demonstrably threatened by North Korean ballistic missiles), a still-open microphone inadvertently recorded a stunning tete-a-tete. The brief but jaw-dropping act of personal diplomacy yoked U.S. and Russian arguments over missile defense systems, a serious international security issue of long-term geo-strategic consequence, to Obama’s short-term domestic political plan to secure his own re-election come November.

The whispered exchange: