A major change came after the Lebanon war: Dozens of reservists were killed after they were thrust into combat in the last days of the invasion. That prompted an outcry, leading the Israeli military to overhaul the system. The military shrank the size of the reserves, cutting many less well-trained members. Today, less than 5 percent of Israel’s population serves in a reserve unit.
The military has created tiers of reservists, from highly trained troops who serve in elite units or pilots who fly fighter planes, to less well-trained people who police settlements in the West Bank or patrol villages along the Lebanese border. But elite reservists are deployed in Gaza, some in units that include professional soldiers.
The diverse economic and social backgrounds of reservists means that some are openly critical of Prime Minister Benjamin Netanyahu of Israel, even as they fervently believe in the military’s mission. Along with their army-issued fatigues, some wear T-shirts emblazoned with the symbols of the mass rallies last summer against Mr. Netanyahu’s overhaul of the Israeli judiciary.
With time on their hands, political debates are common. “You’ll have guys poking fun at each other, saying, ‘I hope you don’t go back to the demonstrations when you go home,’” Dr. Erez said. “It’s not very contentious. People realize that this is something important; they agree that something bigger is going on.”
There are consequences for being too outspoken. On Monday, Israeli news media reported that an air force reservist was fired for criticizing Mr. Netanyahu in a private WhatsApp group. “Political comments while serving in uniform is against the rules,” an Israeli military spokesman said.
Military analysts said the opposition toward Mr. Netanyahu could spell trouble for Israeli commanders if the reservists were asked to take part in operations that could endanger the 240 people being held by Hamas. The government’s handling of the hostages has touched a nerve with the public.
“The risk is that the issue of the hostages is not settled soon, and we see a danger to the hostages in the ground operation,” said Yagil Levy, a professor and expert on the military at the Open University of Israel. “You may see a kind of protest and even resistance among some units in the military.”
In the idle hours, rumors and dark theories can take root. “They tell me that they take a kid who is 8 or 9 years old, pack him with an explosive vest and send him,” Sergeant Schnider said of the militants in Gaza. “What are you supposed to do? I really don’t want to get into that situation.”
While reservists tend to be older and in less prime physical shape than regular soldiers, military officials insist that their training and equipment is up to the task in Gaza or elsewhere. Some former commanders argue that their accomplishments outside the military are a net plus for the war effort.
“The reservists may run slower, but they are level-minded,” said Brig. Gen. Ari Singer, a former chief reserves officer of the Israeli military. “The leadership in the reserves is more authentic, not related to the ranks you have on your shoulder.”
Still, reservists may also become restive if their tours last too long. Many are married with children, and the call-up has disrupted work and family.
Manuel Trajtenberg, the director of Tel Aviv University’s Institute for National Security Studies, estimated that about 500,000 workers were off the clock because of the mobilization and the ripple effects on spouses forced to interrupt jobs to take on domestic duties.
The loss of so much labor, he said, is likely to cause a rare, significant decline in Israel’s per capita economic growth.