SHINDAND, Afghanistan — Across nine square miles of arid flatland in Herat province lies evidence of the shattered past and robust present of Shindand Air Base.

Less obvious is the uncertain future of the second-largest coalition forces airfield in Afghanistan, home to the nation’s fledgling air force academy.

“We’re not going to be here forever,” said Col. John Hokaj, commander of the 838th Air Expeditionary Advisory Group, the U.S. unit in charge of Afghanistan’s first-ever pilot training program. “But we’ll have wasted a lot of money if we just leave in 2016.”

That’s the target date set by the North Atlantic Treaty Organization for the Afghan air force to attain autonomy.

In the interim, the U.S.-led coalition wants to double the ranks of Afghan air force personnel, from 4,000 to 8,000, and increase the country’s fleet to 140 aircraft, more than twice its existing size.

Hokaj considers those ambitions within reach. The unresolved question of what happens to the air force and this base after 2016, however, mirrors the broader quandary for the Afghan military as the majority of coalition forces depart over the next two years.

“It’s a matter of what can the Afghans sustain,” said Hokaj, 46, of Bethel Park, Pa. “That’s something that isn’t known at this point.”

The coalition has nonetheless taken a bigger-is-better approach to Shindand. After an expansion completed last summer that tripled its land mass, the base in western Afghanistan ranks as the largest NATO airfield behind Camp Bastion in Helmand province.

A $500 million upgrade has begun to fill in the extra acreage.

Projects under construction include a training complex and living quarters for Afghan air force recruits and a regional training center for the Afghan national army. The headquarters for an Afghan special forces battalion and a commando brigade are also rising from the dirt, along with new work space and barracks for some 3,000 coalition personnel and contractors.

The building boom follows repairs to the base’s runway, damaged a decade ago by U.S. bombing runs in the early stages of the war against the Taliban.

The repaved airstrip was extended to accommodate unmanned drones, fighter jets and transport planes as large as C-17s. An apron added to the runway provides parking space for dozens of Apache, Black Hawk and Chinook helicopters.

The growth of the base would suggest the U.S. intends to stay beyond 2016.

Apart from coalition efforts to defeat the insurgency in Afghanistan, the airfield’s proximity to Iran, 75 miles to the west, magnifies its strategic importance in the region. Speculation that U.S. forces launch covert operations from the base into Iran has for years drawn persistent denials from military officials.

Yet when talking with their Afghan counterparts, Hokaj and other U.S. officers warn against assumptions of a permanent American presence, despite the Afghan military’s obvious lack of funding and experience to maintain the airfield.

The message of self-reliance, if a concession to the haziness of the U.S. military’s enduring role in Afghanistan, reflects an awareness of the recent past. The fallout after the last foreign army withdrew from the country remains visible on this base almost a quarter-century later.

Remnants of the Soviet era

The Soviet military began building an airfield near the village of Shindand in 1961 and made heavy use of the base during a futile, decadelong siege of Afghanistan that ended in 1989. A few stone structures from the Soviet era still stand, among them an air traffic control tower, since converted into offices for U.S. personnel.

But it is an expanse known as “the boneyard” that holds the most striking vestiges of the Soviet occupation.

The battered husks of dozens of military aircraft litter the brown scrubland over an area the size of perhaps six or seven football fields. Camouflage-painted fighter jets lie in jagged chunks beside gray transport planes and bombers. Huge mounds of rubble — tanker trucks, sheet metal sheds, fuel barrels, chaotic tangles of barbed wire — rust beneath an indifferent sun.

Rebel fighters supported by the U.S. caused much of the damage in the 1980s while battling the Soviet-backed Afghan government. Neglect finished the job.

The Soviets left behind an ample working fleet at Shindand, but within two years, almost none of the planes was operational. Unable to maintain the aircraft, the Afghans stripped them for wiring and parts.

Afghan officers at the base, while agreeing with the need for self-sufficiency, believe the military will require coalition support for up to another decade to avoid repeating history.

“The Afghan people want to be proud of their military and air force,” said Lt. Col. Abdul Hashim, commander of the fixed-wing training program. A former mujahedeen, he fought against the Soviet army and remembers how, after its retreat, the ragtag Afghan forces crumbled. “We want to be on our own. But we are not ready to do everything.”

U.S. personnel share a similar outlook.

“We’d like to see the Afghans be independent,” said Command Sgt. Maj. Keith Davis, 49, of Raleigh, N.C., with the 820th Security Forces Group, the unit that oversees base operations. “But I think we’re going to have to keep a pretty hearty presence if we want this place to stay functioning.”

But as American political and military leaders offer dueling forecasts about U.S. involvement in Afghanistan after 2014, Shindand isn’t immune to the vagaries of war spending.

Two months ago, officials nixed plans for the base’s second runway, a reversal that hints at concerns over mounting security costs in Afghanistan. The 1.3-mile airstrip would have been dedicated to rotary- and fixed-wing training flights for Afghan pilots.

U.S. trainers launched the rotary-wing program in January last year; fixed-wing training started in December. An estimated 70 pilots a year will graduate through 2016, with the Afghan military assigning most of them to coalition airfields in Kabul and Kandahar, where the bulk of the country’s 60 aircraft are located.

‘We will feel more together as a country’

First Lt. Abdul Saboor finished the two-month rotary-wing program late last year. He casts the military’s progression as vital to cultivating a greater sense of national identity in a land deeply divided along ethnic and geographic lines.

“The air force will help the whole military, the whole country,” said Saboor, 39, who grew up in the eastern province of Laghman. “We want to defend Afghanistan, and if the people see us taking control of our security, we will feel more together as a country.”

Transport helicopters that the Soviets abandoned at a handful of bases in Afghanistan make up much of the national fleet and serve as the primary craft for rotary-wing training at Shindand. A dozen Cessna passenger planes, costing a total of almost $11 million, were flown from the U.S. to the base last fall for the fixed-wing program, which lasts 11 months.

Recruits must gain proficiency in English, the international language of aviation, and log long hours in classrooms and flight simulators before taking to the sky.

“We will not carry people through the process,” Hokaj said. “The process is designed to be as rigorous as what we have [in the United States].”

Saboor, regarded by U.S. trainers as one of the best pilots to advance through the rotary-wing program, went up in an aging Mi-17 Soviet helicopter on a sun-soaked afternoon. Joining him were Mohammad Haroon and Abdul Razeq, a pair of 22-year-old Kabul natives in training to become crew chiefs, and a trio of U.S. instructors.

The 90-minute flight was a multilingual affair, with the men speaking a mix of Dari and English, and Saboor reading an instrument panel labeled in Russian. He smoothly guided the helicopter over low-slung mountains shaded ochre, rust, black and brown while Haroon and Razeq traded off crew chief duties, leaning out the open loading door to give directions over the radio as Saboor practiced landings.

Staff Sgt. Christopher Morford, 36, of Tucson, Ariz., worked with Haroon and Razeq. He pointed out nuances in the landscape that might complicate landings and prodded them to scan ground and sky alike for enemy threats.

Haroon was the more attentive student; Razeq dozed off when not standing at the door. But Morford praised both of them after the flight.

“These guys have come such a long way,” he said. “They’re definitely close to being ready.”

For the air force as a whole, by contrast, maturity remains a distant prospect. With rare exceptions, Afghan pilots limit their flying to supply, personnel and medevac runs, leaving combat missions to their coalition allies and pilots with greater experience and superior equipment.

Haroon supplied a fitting analogy for the relationship between his country’s air force and its U.S. advisers.

“When a child is small, he can’t walk, and he gets help from his mother,” Haroon said. “We can’t walk yet. We need the U.S. to stay to help us.”