Editor's note: Peter Bergen is CNN's national security analyst, a director at the New America Foundation and the author of "Manhunt: The Ten-Year Search for bin Laden -- From 9/11 to Abbottabad." Jennifer Rowland is a graduate student at Harvard University's Kennedy School.
(CNN) -- Here are nine reasons to think armed drones are going to be an increasingly common feature of warfare:
1. Given the relatively low costs of drones -- already much cheaper than the costs of a fighter jet and of training a fighter jet pilot -- armed drones will likely play a key role in future conflicts. Armed U.S. Reaper drones, for instance, cost $12 million each and have been frequently deployed against suspected members of al Qaeda, while the F-22 war plane costs around ten times that amount.
2. The virtual monopoly that the United States had on armed drones a decade ago is evaporating. So far, the United States, United Kingdom and Israel are the only nations that have used armed drones in combat.
However, according to data compiled by the New America Foundation, 82 countries now own some type of drone, and while only a small number of those nations possess armed drone aircraft, the new players in the world of armed drones include traditional American adversaries such as China, Russia and Iran.
3. Building drones, particularly armed drones, takes sophisticated technology and access to the specific weaponry that can be launched from an unmanned vehicle. But governments are increasingly willing to invest the necessary time and money either to buy or develop them since armed drones are increasingly seen as an integral part of modern warfare. The Teal Group, a defense consulting firm in Virginia, estimated in 2013 that the global market for the research, development and procurement of drones will more than double in the next decade, from $5.2 billion annually to $11.6 billion a year.
4. Israel is the world's largest exporter of drones and drone technology. The state-owned Israel Aerospace Industries has sold drones and drone technology to more than two dozen countries around the world.
5. Last year the scientific adviser to India's defense minister announced that a state military research firm would begin test-firing precision missiles from drones "in a couple months."
6. A consortium of Euopean countries, including France, Greece, Italy, Spain, and Switzerland, is developing an armed drone prototype called the Dassault nEUROn. France plans to manufacture armed drones for its air force based on this prototype.
7. In February 2013, a regional Russian government posted online and then quickly removed photographs of two Russian-made armed drones. The two systems were reportedly scheduled to begin test flights in 2014.
8. At a 2012 air show in China, Chinese companies displayed full-size armed drones, the CH-4 and Yilong. And the following year a state-run newspaper reported that Chinese authorities had considered using armed drones to kill Naw Kham, a drug lord in Myanmar who was accused of murdering 13 Chinese sailors. In the end, China decided to capture Naw Kham instead of launching a drone strike, but the report showed China's capacity to carry out armed drone attacks. Meanwhile, Taiwan has also been building indigenous drone capabilities, and Taiwanese authorities announced in December that they are developing an armed drone.
9. In 2012, an Iranian military commander, Brig. Gen. Amir Ali Hajizadeh, disclosed details of a new long-range drone that he claimed can fly 2,000 kilometers (about 1,250 miles), which puts Tel Aviv, Israel, easily in range. A year later, Iran announced it would begin mass-producing and exporting the drone, which is supposedly capable of carrying up to eight missiles.