The exchange of rocket fire from Palestinian militants and Israeli airstrikes on the Gaza Strip took a new turn this week when the military wing of Hamas said it had launched drones into Israel -- one of them downed by an Israeli Patriot missile.
The incident, which follows previous launches by the Lebanese militant group Hezbollah on Israel's northern border, marks the potential for aerial surveillance and longer-range attacks using a U.S.-developed technology that analysts have long warned would eventually be mobilized against the United States and its allies.
The drone downed Monday over the southern port of Ashdod lacked the technological sophistication of those flown by the U.S. But at the very least, analysts say, it allowed Hamas to score psychological points against Israel.
Like Hezbollah, Hamas has threatened to use a drone packed with explosives for a kamikaze-style attack on Tel Aviv or other Israeli population centers where Hamas rockets have not inflicted significant damage.
And as a Council on Foreign Relations report noted last month, "drones are, in many ways, the perfect vehicle for delivering biological and chemical agents.''
"Hamas is looking for small victories,'' said Sarah Kreps, a Cornell University professor and coauthor of a new report on drone proliferation. "And to some degree, deploying even a rudimentary drone – whether with real or mock-up missiles – is an accomplishment since it already goes beyond what most states have been able to accomplish.''
More than 80 nations possess drones, but only three – the U.S., Britain and Israel – are known to have fired weapons from drones in combat.
Kreps estimated that the Hamas drone had a 9 1/2-foot wingspan and a range of 160 miles, sufficient to reach almost any part of Israel.
Defense experts say Hamas' first-ever drone incursion could be followed by other, more effective missions if the Palestinian militant group learns to control the remotely piloted aircraft. Any real-time video sent back by a drone would improve Hamas' targeting by providing live feeds and offering feedback on the effectiveness of rocket attacks.
Hezbollah had already demonstrated its ability to provoke Israel with drones. It has launched several that Israel has shot down, the latest in April 2013, according to a recent Rand Corp. report.
Experts say little is known about the capabilities of the Hamas drone shot down Monday. But most agreed that it represented an incremental escalation in the ongoing Israeli-Palestinian conflict and forced Israel to confront a new military challenge.
The drone was probably provided by Iran and assembled in the Gaza Strip, experts said. They are not certain that the drone carried working weapons, although a video provided by Hamas' military wing purported to show missiles strapped under the aircraft's wings. The video has not been authenticated.
If Iran did provide the craft from its own expanding program, a test flight over Israel would permit a test of its capabilities without confronting Israel directly.
"I imagine Iran would like to take one of their drones out for a test spin and get themselves some real-world combat experience," said John Pike, director of Globalsecurity.org. "They'd like to know how fast the Israelis could take it down. Well, they just learned something."
The spread of drone technology into the hands of insurgent groups "is what we've been fearing for a while,'' said Jonathan Schanzer, vice president for research at the Foundation for Defense of Democracies in Washington.
Although questions remain about the sophistication and capabilities of the Hamas drone, Schanzer said, "the Israelis are taking this very seriously.''
Peter W. Singer, who has written extensively about drones and high-tech warfare, said most analysts believe the missiles on the Hamas drone were dummies. "It does not alter the balance of power between Israel and Hamas,'' Singer said.
Hamas has been working on a drone, probably with Iranian help, since at least late 2012, said Jeffrey White, a defense fellow at the Washington Institute for Near East Policy.
Maj. Gen. Shachar Shohat, the chief of Israel's air defense system, told a security conference in Tel Aviv on Monday, "We will have to cope with dozens of pilotless aerial vehicles, in both the northern and southern fronts,'' referring to drone threats from Hezbollah and now Hamas.
Could Hamas fire a lucky shot or crash a drone loaded with explosives into the heart of Israel, triggering panic even if no casualties resulted?
"The type of drones that Hamas would use are intrinsically vulnerable, with no jamming, no onboard weapons and no stealth capability to evade radar," said Loren Thompson, a defense expert at the Lexington Institute, a Washington consulting group.
Several defense experts said they were unable to determine whether Hamas was able to control the drone from a ground-based station in Gaza. Because Israel has already destroyed a drone facility in the Palestinian territory, they said, it would be difficult for Hamas to build the runways and ground control stations needed for an effective program.
And even if they did, "a drone is low and slow,'' said Kreps, the Cornell expert.
Israeli Defense Minister Moshe Yaalon said the drone was an example of Hamas' efforts to find new ways to attack Israel. "Hamas is trying everything it can to produce some kind of achievement, and it's crucial that we maintain our high state of readiness," he said.