The questions swirling around a U.K. base and possible Iranian-backed attacks

British police said they had made a seventh arrest in a murky plot that may have targeted a U.K. airbase. Transcript AILSA CHANG, HOST: There's an airbase in the U.K. that's been in the news a bit. Today, British police say they have made a seventh arrest in a murky plot that targeted this space, which is known as RAF Fairford. Initially, a tip from a local resident led to the arrest of five British nationals in vans outside the base. Later, two Iranian British nationals were arrested, and today NPR confirmed that credible threats of Iranian-inspired attacks led the U.S. to move all of its bombers from this base on Sunday. For more, we're joined now by NPR Pentagon correspondent Tom Bowman. Hi, Tom.TOM BOWMAN, BYLINE: Hey, Ailsa.CHANG: OK, so let's start with the removal of these U.S. bombers. What happened?BOWMAN: Well, right, so after these arrests, the U.S. official said there was additional intelligence information about a credible threat by Iran against the base, which hosted a dozen B-1 bombers which, of course, had been taking part in airstrikes on Iran. The threat was from drones, so the aircraft have returned to bases in the U.S., and of course, already Iran has hit U.S. b...