Army Gen. John Campbell, commander of the International Security Assistance Force, U.S. Forces-Afghanistan, waits to testify before the Senate Armed Services Committee on Feb. 12, 2015. (Photo by Win McNamee/Getty Images)

As Army Gen. John Campbell, the top U.S. general in Afghanistan, prepares to step down from his 18-month command, he cautioned that America’s longest war is at a critical inflection point, and without proper adjustments will repeat the same mistakes of years past.

“A strategic stalemate without end is not the goal of this campaign,” Campbell said, during testimony to the House Armed Services Committee Tuesday, adding that the United States must show flexibility in 2016 or else the new year will be a re-run of 2015. Campbell praised the decision to keep the current U.S. troop strength hovering around 9,000 troops for the remainder of 2016, instead of scaling it back to around 1,000 as President Obama had originally planned.

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Members of Congress, however, voiced frustration that 14 years later the U.S. continues to expend resources in Afghanistan with little tangible outcome. Rep. Walter Jones (R-N.C.), used his  question time to highlight how “sick and tired” the American people are of the war.

“If I didn’t think it was worth it, I would tell my son to do something different,” Campbell said in response to the criticism. Campbell added that his son is an Army Sergeant who had just finished his second tour in Afghanistan and is about to start his third.

Last October the city of Kunduz fell to the Taliban, although it was retaken by Afghan and NATO forces relatively quickly. Large chunks of Helmand province, the Taliban’s birthplace, also fell to the insurgent group. A recent inspector general report stated that the Taliban currently controls more territory in Afghanistan than at any point since 2001.

Campbell pushed back against the report and pointed out that 70 percent of the district centers in Afghanistan are under government control or government influence. Only eight of of 407 district centers are under insurgent control, he said.

One of things Campbell stressed was that the United States’ dedication to the Afghan campaign and continued involvement in Afghanistan is inexorably linked to fighting terrorism and protecting the homeland. Campbell said that terror groups like al-Qaeda and the Haqqani network have been weakened, but still remain a threat. The growth of the Islamic State in eastern Afghanistan has distracted the Taliban, Campbell said, but coalition forces still require resources to contain both groups. He also added that the Taliban has adapted as well by extending the fighting season while also shifting resources to fight the Islamic State.

Militant groups, including the Taliban, the Islamic State and the Haqqani network are “persistent threats that are adapting,” Campbell said, adding that there will need to be a continued forward U.S. presence to contain and defeat them.

Campbell also discussed the current state of the Afghan military and stressed the need for a five year plan for U.S. and NATO support to Afghanistan instead of just planning the war “from fighting season to fighting season.”

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He went on to add that 2015 saw an “uneven but not unexpected” performance by the Afghan Army. While Afghan forces lost territory, Campbell said they also showed an ability to retake lost ground and perform complex security operations.

The Afghan military’s biggest issues, Campbell said, involves poor leadership and a less than stellar ability to field close air support.

Continuing to build the Afghan Army while it fights the Taliban is like “building an airplane while in flight,” Campbell said.

This past month 20 Afghan A-29 Super Tucano propeller-driven bomber aircraft arrived in Afghanistan. Campbell said that only eight will be ready for this next  fighting season. In addition to the A-29, 14 MD-530 little bird helicopters have also entered service as the United States as the Afghan military attempta to phase out older Russian Mi-17 helicopters. The biggest issue facing Afghan pilots in 2016, Campbell said, is getting them comfortable flying at night.

Campbell noted that while it is trying to close the air support gap, the Afghan Air Force was formed relatively late in the war and still requires years of specialized training for its pilots.

“We need to realize that if we recruit a guy now you’re not going to see him [as a pilot] for two to three years,” Campbell said.

Campbell’s replacement, Army Lt. Gen. John W. “Mick” Nicholson Jr, is currently awaiting Senate confirmation to assume command of U.S. forces in Afghanistan. A seasoned veteran of the war there, Nicholson has more experience in Afghanistan than any other current U.S. general.