Why Hamas could emerge stronger militarily from the temporary cease-fire with Israel

While much attention has been paid to the humanitarian relief enabled by the weeklong truce between Hamas and Israel, national security experts note that the pause may have given Hamas the opportunity to strengthen and resupply its forces for when hostilities resumed Friday.

The truce has led to the successful release of dozens of Israeli and other foreign hostages and hundreds of Palestinian detainees held in Israeli prisons. But both Israeli and U.S. officials had previously advocated for "pauses" in the fighting instead of a general cease-fire, suggesting publicly in the weeks before the truce that a general cease-fire would benefit Hamas.

However, as those short-term pauses were extended daily over the past week, they amounted to at least a temporary cease-fire.

The concern was that Hamas would emerge strengthened so its forces could respond to Israel's devastating ground and aerial assault in northern Gaza, and potentially in southern Gaza, where many of the enclave's 2 million civilian residents are now located after heeding Israel's warnings to leave northern Gaza before Israeli forces attacked there.

Those questions of whether Hamas has benefited from the temporary truce may be answered soon as Israel resumed its offensive operations on Friday by launching airstrikes in the Gaza Strip after it said Hamas had violated the terms of the cease-fire.

Earlier this week, a U.S. top national security spokesman acknowledged "a real risk" that Hamas may have benefited from the daily truce extensions to enable the continued transfer of Israeli and other foreign hostages and Palestinian detainees held in Israeli prisons.

"We are watching that closely and our Israeli counterparts, you can bet [they] are watching that closely," John Kirby, the National Security Council spokesman told White House reporters on Monday.

"I would just say that without getting into intelligence issues that any pause in the fighting could benefit your enemy in terms of time to refit, to rest your fighters, to rearm them, re-equip them," said Kirby. "A pause in the fighting can be seen as a benefit but again, I want to stress this was always part of the calculus."

That calculus weighed against the benefits Israel and the U.S. would gain from the return of hostages held by Hamas, according to Kirby.

Mick Mulroy, a former deputy assistant secretary of defense for the Middle East and ABC News contributor, described the pause in fighting as a "net win" for Hamas "both militarily and politically."

"I believe Israel knew this would be the case, but it was worth it for them to recover their hostages," he added.

Mulroy and other national security analysts who spoke with ABC News concur that Hamas has likely used the temporary truce to refit, re-arm, and reposition its forces in Gaza.

"This has stopped the IDF's momentum, allowing Hamas to maneuver to gain a tactical advantage," according to Mulroy.

There have been 15,000 people killed in Gaza and 36,000 injured, according to the Hamas-run Gaza Health Ministry. In Israel, at least 1,200 people have been killed and 6,900 have been injured, according to the Israeli prime minister's office.

While the scale of the destruction to buildings in northern Gaza caused by Israel's airstrikes and ground offensive is very visible, what is uncertain is how much of Hamas' military infrastructure has been destroyed.

"One of the disadvantages that we have is we actually don't know how much of the military apparatus of Hamas has been destroyed or dismantled," said retired U.S. Army Gen. Robert Abrams, former commander of U.S. Forces Korea and an ABC News contributor.

"We don't know how many command posts have been destroyed. We don't know how much of their arms, ammunition, or explosives have been captured or destroyed. The longer there's a cease-fire, it's going to give Hamas an opportunity to rearm, rethink, and reestablish," Abrams said.

But the pause also likely brings risks for Hamas, according to Eric Oehlerich, a retired U.S. Navy SEAL and ABC News contributor, who believes the hostages returned to Israel could have provided intelligence useful to Israel's military.

"When debriefed by IDF planners, the IDF [Israel Defense Forces] will now have increased information on 'how' they were being held. Potentially, 'where' can be figured out if the IDF planners are deliberate and smart, and the hostages most importantly will be able to talk about Hamas' status, motivation, fears etc." said Oehlerich.

But Israeli intelligence gains may have been offset by Israel's agreement to stop flying reconnaissance drones above Gaza at specific times during the truce, Oehlerich added.

"They're going to make their own assessment of where the Israelis are going to strike next. They're going to position their forces to try and not be where they don't want to be and to try and put themselves in a position where they can attack or slow down the Israelis. So, I am sure there is some very furious activity going on," he said.

"Israeli use of overhead surveillance, which they're very good at, is going to be diminished during this time," retired Army Lt. Gen. William Troy told ABC News, speaking while the cease-fire was still in effect. "I would guess that it might frustrate some IDF commanders on the ground, but that's what they're going to have to contend with."

"I'm sure a lot of their weapons are in storage areas that maybe have not been accessible, but now that the Israelis can't fly surveillance all the time, they can get to those places and then they can reposition their forces," Troy added.

Regardless of the success of continued diplomatic efforts to continue the daily truces that have enabled the hostage and detainee exchanges, he said both sides have learned from the previous weeks of fighting in northern Gaza.

"Both sides have already taken lessons as to what works and what doesn't work, and both sides will be trying to adjust their tactics and employ different weapons in different ways," said Troy. "And they will quickly disseminate that information to their forces. And then, when this picks up again -- and it seems like it's inevitable that it will -- they'll try to employ those lessons."