Slowly but surely al-Qaida’s Syria affiliate, Jabhat al Nusra, appears to be positioning itself to emerge as the victor in the U.S.-led war against the Islamic State terror group.

Even more concerning, according to some analysts, is that U.S. policy is playing right into the group's hands with its “excessive” focus on destroying Islamic State while at the same time providing only marginal support to moderate opposition groups.

“Jabhat al Nusra has weakened the moderate opposition and penetrated other Sunni opposition groups in Syria so thoroughly that it is poised to benefit most from the destruction of ISIS and the fall or transition of the Assad regime,” says the Institute for the Study of War in a report Wednesday.

The report goes on to warn that unless the U.S. finds a way to change course, the result could be exchanging one terrorist-led proto-state for another.

“The likeliest outcome of the current strategy in Syria, if it succeeds, is the de facto establishment and ultimate declaration of a Jabhat al Nusra emirate in Syria,” the report said, serving as “a central node in the global al-Qaida network” to export violence to the West.

Stepping up IS campaign

Concerns about U.S. policy regarding Jabhat al Nusra have been growing just as the U.S has been intensifying the military campaign against Islamic State and its self-declared caliphate in Iraq and Syria.

“The momentum is definitely gaining in the coalition’s favor to ISIL’s disadvantage,” Pentagon spokesman Capt. Jeff Davis told Alhurra Television, using an acronym for the terror group.

At a meeting Wednesday in Paris, U.S. Defense Secretary Ash Carter encouraged Washington’s European allies to step up their efforts.

"We agreed that we all must do more,” Carter said.

French Defense Minister Yves Le Drian agreed.

“It is the moment to increase our collective forces with a coherent military strategy,” he said.

But the authors of the ISW report caution such Western rhetoric is part of the problem, allowing Jabhat al Nusra to fly under the radar.

“The group has the same objective and the same ultimate end state as the Islamic State,” said ISW analyst and report co-author Jennifer Cafarella. “They’re trying to build a base of local legitimacy from which in the future to launch attacks against the West.”

But unlike Islamic State, which has sought to impose its caliphate, the report’s authors argue Jabhat al Nusra has managed to intertwine itself with the Syrian population and embed itself within key opposition groups.

They also say Nusra, which has long opposed the upcoming peace talks for Syria, is poised to pick up support from additional rebel factions who feel they have been shut out by the process.

U.S. officials: Nusra, unlikely to emerge

Still, some U.S. officials argue the emergence of a Jabhat al Nusra emirate is an “unlikely outcome,” pointing out the group has not been ignored in the drive to destroy Islamic State.

“The leadership and their staffs, both military and civilian, are definitely considering the second and third order effects,” the official told VOA on condition of anonymity. “They are not being supported either directly or indirectly.”

U.S. officials also contend that pursuing a political solution will also work against Jabhat al Nusra’s ambitions.

“Such a result would provide the basis for a consolidated front against various radical groups including Nusra and ISIL,” a U.S. intelligence official told VOA.

Other officials and analysts point out that while the majority of the U.S.-led airstrikes have targeted Islamic State, al Qaida and Jabhat al Nusra operatives have also been hit.

Yet some say Jabhat al Nusra, though not the biggest or strongest of the various Syrian factions, is positioned well enough to survive and eventually thrive.

“What makes Jabhat al Nusra one of the most lethal forces is that it’s a very skilled tactical group, with fighters with a tremendous amount of experience,” said Nathaniel Barr, a research manager at Valens Global who has written about the group’s exploitation of U.S. strategy.

“Ultimately Nusra’s the one that has the more sustainable long-term strategy,” he said. “We run the risk of missing that strategy, of allowing them to further entrench if we continue to pursue the status quo.”