JERUSALEM — Israel's Iron Dome rocket shield has aced its first serious test.
Gaza's Hamas rulers have been careful to stay on the sidelines.
And Islamic Jihad - now closer to Iran than is its larger rival Hamas - is taking the lead in this round against Israel.
These are some of the trends emerging from four days of fighting between Israel's air force and Gaza rocket squads, triggered by Israel's killing of a militant leader last week.
Twenty-three Palestinians have been killed, including five on Monday, and about 1 million Israelis in rocket range have seen their lives disrupted by the threat of rocket attacks, with frequent sirens warning them to run for cover.
Egyptian truce efforts appeared to stall, as both sides said they were willing to keep fighting.
Israeli Prime Minister Benjamin Netanyahu warned that Israel would keep striking those trying to harm Israeli civilians and that the Jewish state is "ready to broaden its operation."
Gaza militants insisted that Israel stop firing first and that it promise to halt airstrikes aimed at killing Gaza militants for good, a guarantee Israel is unlikely to give.
Egypt sided with the Palestinians in their demands.
In Israel, government officials and missile experts praised the performance of Iron Dome, an Israeli-made system designed to shoot down short-range rockets like those fired from Gaza.
Iron Dome has been rolled out over the past year, and the current fighting poses its most serious test. Israel has other systems deployed against longer-range missiles.
Iron Dome uses cameras and radar to track incoming rockets and intercepts only those that would pose a threat to people and property, ignoring those that are expected to fall in open areas.
The military said that of 143 rockets fired since Friday, it tried to intercept 63 and succeeded in all but nine of those attempts.
No Israelis have been killed in the current fighting, and property damage has been relatively minor.
Uzi Rubin, a missile expert and former Defense Ministry official, said Iron Dome has exceeded expectations.
"The performance up to now has been almost flawless," Mr. Rubin said, adding that the perception could change quickly in the event of casualties.
Critics noted that each intercept costs about $100,000, arguing that the cost could be prohibitive if Israel were fighting a full-fledged war.
In the current round, Islamic Jihad, the second largest militant group in Gaza, has taken the initiative.
Islamic Jihad has maintained close ties to its sole sponsor, Iran, while Hamas has drifted away from its longtime patron in disagreements over Syria's brutal crackdown.
Iran has punished Hamas for refusing to side with Syrian President Bashar Assad, including by cutting funding to it.