LONDON — The Obama administration has a doctrine. It’s called the doctrine of silence. A radical shift from President Bush’s war on terror, it has never been set out to the American people. There has seldom been so big a change in approach to U.S. strategic policy with so little explanation.

I approve of the shift even as it makes me uneasy. One day, I suspect, there may be payback for this policy and this silence. President Obama has gone undercover.

You have to figure that one day somebody sitting in Tehran or Islamabad or Sana is going to wake up and say: “Hey, this guy Obama, he went to war in our country but just forgot to mention the fact. Should we perhaps go to war in his?”

In Iran, a big explosion at a military base near Tehran recently killed Gen. Hassan Tehrani Moghaddam, a central figure in the country’s long-range missile program. Nuclear scientists have perished in the streets of Tehran. The Stuxnet computer worm has wreaked havoc with the Iranian nuclear facilities.