Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. As Attack Drones Multiply, Israeli Firms Develop Defenses Associated Press YEHUD, ISRAEL - Israel, one of the pioneers of drone warfare, is now on the front lines of an arms race to protect against attacks by the unmanned aircraft. A host of Israeli companies have developed defense systems they say can detect or destroy incoming drones. But obstacles remain, particularly when operating in crowded urban airspaces. "Fighting these systems is really hard ... not just because you need to detect them, but you also need to detect them everywhere and all the time," said Ulrike Franke, a policy fellow at the European Council of Foreign Relations. Drones present unique challenges that set them apart from traditional airborne threats, such as missiles or warplanes. They can fly below standard military radar systems and use GPS technology to execute pinpoint attacks on sensitive targets for a fraction of the price of a fighter jet. They can also be deployed in "swarms," which can trick or elude conventional defense systems. Even small off-the-shelf drones can be turned into weapons by rigging them with explosives or simply crashing them in crowded areas. A series of drone strikes across the Middle East, including an attack on a Saudi oil field and processing plant that jolted international markets earlier this month, have underscored the devastating effectiveness of small unmanned attack aircraft. The drone attack on Saudi energy infrastructure knocked out about half of the kingdom's oil supplies. .