But their common foe, Iran, is in the race, too, and that has serious implications for the military balance in the Middle East.
Iranian President Mahmoud Ahmadinejad unveiled a long-range, bomb-carrying drone called the Karar, Farsi for "assailant," in August that reputedly has a range of 600 miles and can carry a military payload of 450 pounds.
That's not enough for the jet-powered UAV to reach Israel -- but it could if it was launched from Lebanon or Syria by Iran's allies.
With the Levant simmering amid rising tension over Iran, Iraq and the Middle East peace process, the Iranian drive to develop long-range UAVs is causing concern in Israel and pro-Western Arab states such as Egypt and Saudi Arabia.
Hezbollah of Lebanon, Iran's main proxy in the Arab world, allegedly has as many as 45,000 rockets and missiles provided by Iran and its ally Syria and since 2004 has operated the Iranian-built Mirsad-1 UAV.
This has been used to carry out aerial reconnaissance over Israel, much to the annoyance of the Jewish state's military. Mirsad is an early generation, relatively unsophisticated system with little endurance capability and doesn't, as far as is known, carry weapons.
But the more advanced versions of the Karar, which Iran presumably has in the works, would be a very different story.
It could, conceivably, be upgraded to perform the kind of deadly remote-control attacks that the U.S. MQ-1 Predator or its successor, the MQ-9 Reaper, are conducting in Afghanistan and Pakistan against al-Qaida and the Taliban.
These craft are produced by General Atomics Aeronautical Systems.
Global security analyst Paul Rogers, professor of peace studies at Britain's Bradford University, noted recently that the current phase of developing these craft as instruments of war is to apply the stealth and weapons technologies developed for the Lockheed F-117A Nighthawk and the Northrop Grumman B-2 bombers.
By giving UAVs radar-evading capabilities, these craft could fly over Iran or other hostile states "with impunity, and with minimal fear of interception," Rogers observed.
The Pentagon's Defense Advanced Research Projects Agency is planning a new generation of fast and heavily armed UAVs.
"A current project is to adapt the Fairchild A-10 -- among the world's most powerful close-air support planes -- for autonomous operations," Rogers wrote.
The A-10, known as the "Warthog" because of its seemingly ungainly lines, carries a fearsome array of weapons that include a 30mm cannon, laser-guided rockets, AGM-56E Maverick air-to-ground missiles and GPS-guided bombs.
The next-generation UAV platform would thus combine "the intense firepower and high subsonic speed of the A-10 with an endurance of up to 18 hours," Rogers noted.
The Israelis, considered to be the second-ranking UAV producer after the United States, is the world's top drone exporter with more than 1,000 sold to 42 countries, says Jacques Chemia, chief engineer at the UAV division of state-owned Israel Aerospace Industries, flagship of Israel's defense industry.
Israel's military employs a wide array of UAVs, including armed craft deployed against Hezbollah and Palestinian Hamas militants.
It is also reported to fly surveillance drones over Iran, presumably to locate targets for threatened pre-emptive strikes against the Islamic Republic's nuclear infrastructure.
Israel reportedly used long-endurance IAI Heron drones to spot Iranian arms consignments bound for Hamas in Gaza across the Red Sea to Sudan in early 2009 -- and to destroy two convoys loaded with weapons in the desert.
With Iran now pushing its growing technological expertise to develop intercontinental ballistic missiles and spy satellites, its efforts to produce long-range UAVs may not be too far off.
"The Karar may well be unarmed and have limited intelligence capabilities," says Rogers, "but its very existence will reverberate …
"If the Iranians have been able to develop a long-range drone, then it is more likely that they will attempt to launch reconnaissance drone sorties against Israeli territory -- at a time of their own choosing.
"The military effect will be minimal but the political impact will be very great … The role of drones in asymmetric warfare -- or even just asymmetric psychological warfare -- may come much sooner than many expect."