TAMPA, Florida — Fighting simmering frustration in their ranks over ISIS advances in Iraq and Syria, top U.S. special operations commanders say they are building forces for a multi-generational fight—not a war that will be won in the next few years.

“We recognize this is a longterm prospect,” said Gen. Joseph Votel, the overall leader of U.S. Special Operations Command, in remarks to The Daily Beast during a special operations forum in Tampa. “We’re patient.”

“We talk about it being a 15-year struggle,” added Lt. Gen. Bradley Heithold, who heads the Air Force Special Operations Command, said describing the fight.

But many special operations officers and troops both in Tampa and Washington don’t want to wait that long to take the fight to ISIS. They were eager to talk about their aggravation over fighting by remote in Iraq and Syria: having to advise Iraqis, Kurdish Peshmerga, and rebel Syrian fighters from afar instead of joining them in battle.

“We are doing everything through cellphones… It’s hard to do much when you can’t go outside the wire,” said one special operator, using the military jargon for the perimeter of a base.

They blame the hands-off approach on an Obama administration unwilling to risk even small numbers of American lives in battle, burned by the fallout of the loss of four Americans in Benghazi, Libya, and intent on preserving the legacy of President Barack Obama’s troop drawdowns in Iraq and Afghanistan.

“You can’t say ‘We’re with you every step of the way, except when you are going on combat operations,’” said a former senior special operations official briefed on the ISIS campaign.

He and many other officers, current and former, at the conference believe both Mosul and Ramadi could have withstood the assault of the so-called Islamic State, also known as ISIS, if a small number of U.S. military advisers had been working with Iraqi forces at the front lines.

They spoke on condition of anonymity because they were not authorized to publicly discuss the debates over war strategy.

“They know as long as there are Americans with them, that if they get in trouble, there is intelligence,” and medical evacuation, the former senior official said. “They don’t have faith in their own chain of command to do it, so rather than being captured and slaughtered by ISIS, they’ll break and run.”

Another former senior special operations officer said this is the normal tension that occurs every few years between America’s political leadership that weighs the public’s reaction to U.S. casualties, and a group of professional risk-takers who want to fight alongside those they’ve trained to fight.

“It’s a generational thing,” said the officer, who said U.S. forces were similarly frustrated when training Nicaraguan forces in the 1980s. “Every few years, there is a place where the U.S. administration won’t let U.S. forces accompany those they’ve trained,” the officer said. “This younger generation has to get over it.”

U.S. Central Command’s program to train Syrian rebels—a special operations mission—has been delayed partly by congressional funding delays, and partly because it’s been difficult to find trustworthy candidates without being inside Syria, according to current and former U.S. officials involved in the process.

Votel said he hadn’t heard that vetting was a problem, nor had he heard frustrations expressed over the pace of the fight.

But faced with the necessity of having to fight by remote, the special operations commanders asked industry members present at the National Defense Industry Association conference to find new ways for the Americans to communicate remotely with foreign partners in the field—a necessity in places like Syria, where U.S. troops rely on Kurdish and other foreign partners to relay intelligence and targeting information by cellphones that can be hacked or intercepted.

The head of the Navy SEALs, Rear Adm. Brian Losey, said the nature of the fight is changing who they’re recruiting, with SEALs needing to raid one day, and work with dipomats, intelligence officers, and foreign officials the next.

“We’ve started to put more value on intellect,” Losey said, with almost half the incoming enlisted SEALs in the past two years having college degrees.

Frequently working in small, far-flung teams, “they are representing America all by themselves,” he said.

While some of the special operations commanders at the conference privately voiced concern over ISIS’s recent advances, they all said this will be a decades-long war that requires a lot more than U.S. military firepower to win.

“In this struggle, you don’t kill your way to victory,” added Heithold. “You do have to put pressure on the leadership in order to affect them. But it is not in itself the answer.”

“That’s why we talk about it being a 15-year struggle,” he said.

“We can continue to mow the grass and try to take ’em out, but it’s not a winning strategy,” added Lt. Gen. Charles Cleveland, the head of U.S. Army Special Operations Command. “We’re going to have to start thinking of root causes,” like instability or economic deprivation—something that the military can only really contribute to by training local forces, leaving the rest to other branches of government.

“We have to try to set the conditions so that 8-year-old today doesn’t become the jihadi in 10 years… or even less than that,” he said.