U.S. counterterror officials are warning of an increased risk of an attack this summer, given al-Qaida’s apparent interest in summertime strikes and increased al-Qaida training in the Afghan-Pakistani border region.On Tuesday, Homeland Security Secretary Michael Chertoff told the editorial board of The Chicago Tribune that he had a “gut feeling” about a new period of increased risk.

He must watch Stephen Colbert.

“Summertime seems to be appealing to them,” Chertoff said in his discussion with the newspaper about terrorists. “We worry that they are rebuilding their activities.”

Yes, much like sunflowers, terrorists love the summer. And we all know which way the sun sets — when they face the West, here come the terrorists!

But maybe he has a point:

Al-Qaida and its sympathizers have shown an interest in summertime attacks. Some examples from recent years:

• In 2005, London faced two separate sets of transit attacks. The July 7 attacks on three trains and a bus killed 52. A second attack on July 21 was bungled when the detonators failed to light the explosives.
• Last summer, international counterterror authorities said they foiled a plot to use liquid explosives to take down roughly 10 U.S.-bound airliners leaving Britain.