military drone was shot down over Iranian airspace,

On Wednesday November 30th an unmanned United States military drone was shot down over Iranian airspace, about 140 miles from the border of Afghanistan. The fallen drone, packed with guarded US military secrets, highlights the Obama administrations growing reliance on unmanned aircraft to fight its wars.

Unmanned drones have been a signature of the United States fight against terrorism; according to the Washington Post, U.S. drone strikes have killed twice as many suspected Al-Qaeda and Taliban members than were ever imprisoned in Guantanamo Bay. President Obama has found them particularly useful, authorizing more drone strikes in the first nine months in office than President George W. Bush did in his final three years in office.

If the recovered drone is in good shape it could provide Iran, and their allies including China and Russia, with highly guarded US military secrets, causing a fair amount of anxiety in Washington.

However, pursuing the enemy while keeping soldiers off the battle field is not a new strategy. The practice began in the 1940's when the U.S. started using unmanned rockets, and has evolved to the point where military drones are an integral part of any modern arsenal.

The United States has flown over 300 drone missions as of October of 2011, and while they're a crucial tool in modern warfare, the Bureau of Investigative Journalism believed they are to blame for hundreds of civilian casualties; a number the Pentagon denies.

Looking forward, what's the future of this joystick warfare, and is it legal? On Around the World, Christiane Amanpour is joined by Peter Singer, senior fellow at the Brookings Institute and author of Wired for War to talk about the future of drones.