CAIRO — They smuggle the parts or make their own, aided with know-how from Iran. They repurpose plumbing pipes scavenged from abandoned Israeli settlements and components culled from dud Israeli bombs. They assemble the rockets underground or in dense neighborhoods that the Israelis are reluctant to strike.
Despite Israel’s vaunted surveillance capability and overwhelming military firepower next door, Palestinian militants in Gaza have managed to amass a large arsenal of rockets with enhanced range in the 16 years since Israel vacated the coastal enclave it had occupied after the 1967 war.
Hamas, the militant group that has run Gaza since 2007 and does not recognize Israel’s right to exist, has parlayed the arsenal into an increasingly lethal threat, as seen in the most recent upsurge of hostilities with the Israeli military. By Thursday, Israeli officials said, the militants had fired about 1,800 rockets.
The arsenal pales in comparison to the vast destructive powers of Israel’s air force. But to Israelis, the rockets are the tools of what their country and many others including the United States regard as a terrorist organization, embedded among the nearly two million Palestinian inhabitants of Gaza.
Michael Armstrong, an associate professor of operations research at Brock University in Canada, found a significant increase in the rate of fire. Using numbers from the Israel Defense Forces, Mr. Armstrong, who studies these weapons, cited 470 rockets fired from Gaza during the first 24 hours of the most recent escalation compared to a peak of 192 rockets per day in 2014 and 312 in 2012.
Hamas, he says, also launched more long-range attacks with 130 rockets fired at Tel Aviv late Tuesday, representing close to 17 percent of all fired until that point. In 2014 that rate was at eight percent and in 2012 at less than one percent.
“We still don’t know if Hamas has more long-range rockets, or if they are choosing to use their best stuff first,” Mr. Armstrong said.
Michael Herzog, an Israel-based international fellow at The Washington Institute for Near East Policy and a retired brigadier general in the Israel Defense Forces, said Israeli military and intelligence officials are now far more concerned about the abilities of the militants to produce rockets they once had to import.
“The focus of I.D.F. targeting now is on the production facilities so that when this round of fighting ends, there will not only be less rockets but also less production capabilities for making them,” Mr. Herzog said.