Since Tuesday, Palestinian Islamic Jihad (PIJ) has fired hundreds of rockets into Israel from the Gaza Strip. Hamas, which rules Gaza, seems to have avoided joining in, adhering to the strategy of low-level conflict it has pursued since autumn 2014. To Hillel Frisch, the current round highlights the differences between the two terrorist groups:

While Hamas views the use of violence as a means for increasing the volume of trade with Israel and securing the inflow of Qatari money, both of which enhance the welfare of its hardcore supporters and of the Gaza population at large, Islamic Jihad seeks full-fledged confrontation as part of an Iranian strategy to deflect attention from its Syrian military buildup and regional expansion.

These strategic goals reflect the differences in the political and organizational makeup of the two terror groups. A Sunni organization with popular support that is clearly identified with the wider Muslim Brotherhood movement, Hamas operates like fish in water in a society that is almost exclusively Sunni, with most of its members being truly devout. If there are any Gazan Shiites, they keep their beliefs and practices strictly to themselves.

There is a world of difference . . . between Hamas and Islamic Jihad, which is known for its strong links to Iran and which has no popular base. Though they value PIJ for its sacrifices, most Gazans suspect its members of being Shiites in disguise. A form of love-hate relationship thus prevails between the general population and PIJ, a disposition that has become more pronounced as the conflicts between Shiites and Sunnis in Syria, Iraq, and Yemen have intensified.

[But] Islamic Jihad’s paltry popular base means its dependence on Iran is all the greater. For [one thing], the organization can operate purely as a fighting arm without the need to take into account the welfare of the Gaza population. [Moreover], Hamas cannot afford to bring an immediate end to the rockets. [It] can only constrain, rather than stop, PIJ because it needs Iran as well.

While I’ve seen much speculation—some reasonable and well informed, some quite the opposite—about why Jerusalem chose Friday morning to begin its campaign against Iran, the most obvious explanation seems to be the most convincing. First, 60 days had passed since President Trump warned that Tehran had 60 days to reach an agreement with the U.S. over its nuclear program. Second, Israeli intelligence was convinced that Iran was too close to developing nuclear weapons to delay military action any longer. Edward Luttwak explains why Israel was wise to attack:

Iran was adding more and more centrifuges in increasingly vast facilities at enormous expense, which made no sense at all if the aim was to generate energy. . . . It might be hoped that Israel’s own nuclear weapons could deter an Iranian nuclear attack against its own territory. But a nuclear Iran would dominate the entire Middle East, including Egypt, Jordan, the United Arab Emirates, and Bahrain, with which Israel has full diplomatic relations, as well as Saudi Arabia with which Israel hopes to have full relations in the near future.

Luttwak also considers the military feats the IDF and Mossad have accomplished in the past few days:

To reach all [its] targets, Israel had to deal with the range-payload problem that its air force first overcame in 1967, when it destroyed the air forces of three Arab states in a single day. . . . This time, too, impossible solutions were found for the range problem, including the use of 65-year-old airliners converted into tankers (Boeing is years later in delivering its own). To be able to use its short-range F-16s, Israel developed the “Rampage” air-launched missile, which flies upward on a ballistic trajectory, gaining range by gliding down to the target. That should make accuracy impossible—but once again, Israeli developers overcame the odds.