Here’s a jaw-dropping statistic to keep in mind while wondering whether more can be done to prevent terrorists in places like Yemen from mailing bomb packages to the United States.

On the day last week when terrorists in Yemen did just that—one via FedEx, the other via UPS—the total number of packages that both shipping companies sent out of Yemen was 13.

That’s 13 packages total, according to a U.S. law-enforcement official, including the two that contained the bombs.

In other words, there is no good reason why this attempted attack could not have been pre-empted from the get-go. It’s not as if the shipping clerks were too busy to take much notice when a customer approached them with an order to ship what she said was a printer to Chicago.

A shipping clerk in London or Paris might be forgiven for letting a suspicious package slip through out of the thousands that move in and out in the course of a day. But letting two out of 13 go through?

Since Yemen has been officially designated a central swamp of al-Qaida activity, one would think that the local employees of the two major U.S.-owned shipping companies might be trained—if not required by law—to follow certain procedures when someone tries to ship anything to a Western country, or at least anything bigger than the slenderest of envelopes.

The bombs in these packages appear to have been so well-hidden that even a sophisticated government scanner would not have detected them. (The packages were found only because an informer, working for the Saudi government, supplied their tracking numbers.) But as the security officers for Israel’s El Al airline can attest, a few probing questions can make a bomb-smuggler sweat—and any display of nervousness would then warrant a thorough inspection of the luggage and more.

Some questions that the FedEx and UPS clerks should have asked the bomb-shippers that day, as a matter of policy if not second nature: Who is this person in Chicago that you’re sending this to? How do you know him? Why does he need someone to send printing supplies from Yemen?

(By the way, according to one U.S. security consultant, the packages were addressed not to two synagogues—the terrorists weren’t that explicit about their intentions—but to two addresses where synagogues are, or at one time were, located.)

Faced with this interrogation, the customer might have walked away: plot foiled. Or she might have hesitated a bit too long over one answer or another—justifying a closer look at the situation, a calling-in of the authorities, at very least a delay in putting that package on a plane.

But here’s another fact worth pondering. The FedEx office in Yemen is not a branch of FedEx; it’s a franchise, run by someone who pays a fee to use the company logo. In a phone interview this afternoon, Ann Saccomano, a FedEx spokeswoman at corporate headquarters in Memphis, Tenn., said of the office in Yemen: “We use a global service participant. We don’t service it directly.” The people who work in that office, she added, “are not FedEx employees.” (Update Nov. 1, 3:55 p.m.: After this piece was published, a UPS spokesman confirmed that the same is true for its operations in Yemen.)

Saccomano would not discuss who runs these global service participants, how their employees are hired, what kinds of security measures are taken to assure their reliability, or how many packages they tend to handle each day. Neither would Sock Hwee Tan, a spokesperson for UPS, who said in an e-mail response to similar questions, “We consider such information to be confidential and proprietary.”

There may be reasons for keeping this kind of information confidential—but not proprietary.

A simple syllogism should be at work here: Terrorists put bombs inside airplanes; certain countries are swarming with terrorists; U.S.-licensed companies that are based in those countries and that put anything inside airplanes should be operated by company employees and follow strict, government-imposed security policies—and if they fail to do so, the offices should be shut down or taken over by U.S. marshals.

For the moment, FedEx and UPS have suspended operations in Yemen—though it’s worth noting that Afghanistan and Pakistan are among the 220-plus countries and territories where they still have offices up and running. What’s going on in those offices? Someone high up should find out.

Become a fan of Slate on Facebook. Follow Slate and the Slate Foreign Desk on Twitter.