Speaking at the Institute for National Security Studies at Tel Aviv University, former CIA director and Gen. (ret.) David Petraeus issued a serious warning about the international threats posed by shoulder-fired surface-to-air missiles (SAM), also known as man-portable air-defense systems (Manpads), in the hands of Al Qaeda and other terrorists.

Petraeus referred to the Jan. 27 downing of an Egyptian military helicopter by a Russian Strela-2 missile (a.k.a. SA-7) by Al Qaeda-affiliated Ansar Beit al-Maqdis in the Sinai Peninsula. “Shooting down a helicopter with an apparent shoulder-fired missile is a big deal. . . . Our worst nightmare [was] that a civilian airliner would be shot down by one,” he said. “ . . . The concern over an attack on civilian aviation flows not only from the loss of passengers' lives but also from the likely economic consequence that would follow: a worldwide grounding of air traffic that might bring the global economy to a screeching halt.”

The threat of Manpads in the hands of Al Qaeda and other terrorist groups has escalated dramatically. After rebels killed Moammar Gadhafi in Libya in 2011, 20,000 Manpads went missing. Months later, only 5,000 reportedly had been destroyed. Where the remaining missiles are is unclear. While the Obama administration issued a statements assuring Americans that most of Libya's weapons, including Manpads, have been secured, NATO's then-military committee chairman, Adm. Giampaolo di Paola, was not so sure. His fear that Libyan Manpads could be scattered “from Kenya to Kunduz [Afghanistan]” subsequently materialized.

Libyan, Iranian and possibly Syrian Manpads found their way to Salafi Bedouins, Hamas and Al Qaeda-affiliated terrorist groups in the Sinai, forcing restrictions on Israeli military and civilian air traffic in the area. A year after Gadhafi's fall, Israeli officials reported an SA-7 had been fired at one of their military aircraft over the Gaza Strip. In early 2012, a Bedouin Tarabeen tribe leader in the Sinai told CNN: “We have smuggled thousands of shoulder-launched SAMs to Gaza through the tunnels . . . and we saved some for us.”

Around that time, Aviation Week reported that Manpads from Libya, including the advanced Russian-made SA-24 Grinch SAMs, “were apparently smuggled to Iran where they were then sent to Iran's proxy force, Hezbollah, in Lebanon, and Hamas in the Gaza Strip” (AW&ST March 12, 2012, p. 27). In August 2013 and twice in September, growing Al Qaeda activities forced El Al Israel Airlines to suspend flights to the southern resort city of Eilat. And in October 2013, “Dutch charter airline Transavia . . . canceled flights to . . . Sharm el-Sheikh . . . [because of] threats from the ground in the [surrounding] Sinai area.”

Evidence that Al Qaeda in the Magreb has been training its fighters to use Gadhafi's SA-7 Manpads was discovered last year by the Associated Press. A “Dummies' Guide to Manpads,” written in Arabic, was discovered at a “Jihad Academy” in Timbuktu, Mali. Indeed, growing jihadi activities in the Sahel have elevated threats to energy installations in not only Mali but also the entire region. And early this month, following his visit to Moscow, Syrian opposition leader Ahmad Jarba declared that he was expecting anti-aircraft weapons (Manpads), but did not say who would supply them. These deadly missiles have a 10,000-ft. range.

U.S. aviation security experts argue that the threat to America's civil aviation fleet posed by Manpads is minimal. They say the cost of equipping passenger aircraft with Manpad countermeasure devices—estimated at $43 billion—is prohibitive and unjustified. However, if a single missile found its way to Hezbollah operatives in Mexico and then was smuggled into the U.S. and fired at any of the 7,000 aircraft in the civilian fleet, the struggling U.S. economy would be devastated in a flash. This time, U.S. government officials and airline executives could not claim they were unaware of the threat. They would be held responsible for hundreds of deaths.

The most advanced, well-tested, lightweight system available today is Elbit Systems' Multi-Spectral Infrared Countermeasures family of defensive aids for aircraft and helicopters. Measuring 2.7 meters (8.9 ft.), the system's hardware can be installed on an aircraft's exterior or inside the fuselage. An externally mounted C-Music pod weighs only 190 kg (418 lb.) and can be transferred to another aircraft in about 40 min. A lighter, 160-kg variant is designed to fit inside an aircraft.

The threat of Manpads, which can cost as little as $5,000 apiece on the black market, to U.S. commercial aviation is real and present. Protection is needed now. If the U.S. government refuses to act, insurance companies should demand that airlines install available protective systems. Airline owners will resist, claiming the cost of $1.5-3 million per system, is too high. But passengers would probably be willing to trade higher ticket prices for assured protection from Manpad attacks.

Rachel Ehrenfeld is a director of the American Center for Democracy.