Heritage’s James Carafano writes about the Airborne Laser, “a defensive weapon once ridiculed as science fiction”:

Skeptics even persuaded the Obama administration to slot the airborne laser for the ninth circle of procurement hell — a pit for dead-end research and development programs.

The Airborne Laser (ABL) has now been tested, and:

It is proven.
But don’t expect high-fiving in the White House. The administration already passed on the option to build a second test aircraft. Rather than add the ABL to the military’s arsenal, the administration seems more than willing to let the project end as a successful science experiment.

An ABL could help neutralize the threat of “Scud in a bucket,” which, Jim says, in many ways is “the ultimate weapon”:

It could sail close to U.S. waters without being subject to inspection by the Coast Guard or Customs. The enemy could fire the missile and scuttle the ship, leaving no record of who launched the attack.
If Iran has one missile and nuclear weapon, it might have two. It could detonate one over New York in a low-altitude air burst that would kill up to a half-million and cripple Manhattan forever.
Iran could fire a second at high altitude over the mid-Atlantic states, creating an electro-magnetic pulse that would take down a large portion of the national grid and plunge Washington, D.C., into permanent darkness.
America would be crippled in a flash, with no obvious enemy at which to shoot back.