The money seems like a pittance for Egypt, which has a $256 billion economy. But the $1.3 billion in military aid that the United States gives the country every year is its main access to the kind of big-ticket, sophisticated weaponry that the Egyptian military loves.

In fact, Egypt is so enamored of Apache attack helicopters, M1A1 battle tanks and F-16 fighter jets that exasperated American military officials have been telling generals there for years that they need to expand beyond the hardware of bygone wars and spend more American money on border security, as well as counterterrorism and surveillance equipment and training that a truly modern military needs.

Either way, a close look at the details of American military aid to Egypt shows why the relatively modest $1.3 billion may give the United States more leverage over the Egyptian military than it may seem, although still not as much as it wants.

Even if Saudi Arabia and other Persian Gulf monarchies make up for any aid the United States may suspend, Washington would block Egypt from buying American weaponry with that money — a serious long-term problem for a military that is already viewed as sclerotic and has neglected pilot training so badly that the Egyptian air force has one of the worst crash rates of any F-16 fleet in the world.What Egypt’s generals fear most is the cutoff of hundreds of millions of dollars in mundane but essential maintenance contracts that keep the tanks, fighter jets and helicopters running, American officials and lawmakers said. In the past, maintenance costs have represented roughly 15 percent of total American military aid to Egypt, according to the Government Accountability Office.

“The spare parts and maintenance of this military equipment that we’ve given the Egyptians is important to their capabilities,” Senator John McCain, Republican of Arizona, told CNN on Sunday.

Or as Robert Springborg, a professor at the Naval Postgraduate School in Monterey, Calif., and an expert on the Egyptian military, put it this week, “Without that sustainment money, planes won’t fly and tanks won’t drive.”

Of course, if American aid for spares and maintenance was suspended, Egypt could cannibalize parts from its existing fleets of tanks, planes and helicopters — probably for some months or even a few years, procurement experts said. With no external threat on Egypt’s borders, the Cairo government would not jeopardize protection to the country.

Similarly, canceling helicopters and tank kits would be a symbolic blow — American military aid covers as much as 80 percent of Egypt’s weapons purchases, according to a recent Congressional Research Service report — but would not immediately decrease the capability of Egypt’s armed forces.

At the same time, cutting off American military aid presents its own complications for the United States and could ensnarl the Obama administration in a knotty contractual battle with American military contractors, said military procurement specialists and Congressional aides.

Under current procedures, Egypt can submit large orders in advance for weaponry and equipment that takes years to produce and deliver, under the assumption that Congress will continue to allocate the same $1.3 billion in military aid year after year. Some Egyptian orders now extend to 2018 under this arrangement, called cash-flow financing. In effect, officials said, the United States has handed Egypt a credit card with a maximum limit of billions of dollars — a perquisite extended only to Egypt and Israel.

The administration has told Congress in recent days that canceling weapons and maintenance contracts could force the government to incur as much as $2 billion in penalties. Under the terms of the tank program, for example, most components are produced in the United States — Ohio, Michigan, Alabama, Florida and Pennsylvania — and shipped to a facility outside of Cairo for assembly.
Obama administration officials insisted on Tuesday that all aspects of the relationship with Egypt were under review, including the military aid, even as a White House spokesman dodged questions on whether aid had been held up pending the review.

“Providing foreign assistance is not like a spigot,” Josh Earnest, the spokesman, told reporters. “You don’t turn it off and on or turn it up and down like a faucet. Assistance is provided episodically.”
Military aid has served as a foundation of the American relationship with Egypt for more than three decades. In basic terms, the aid acts as an annual incentive payment to Cairo for abiding by the 1979 peace treaty with Israel. The arrangement initially also sought to wean Egypt off its longtime arms supplier, the Soviet Union.
“The aid’s primary purpose has been to obtain access for U.S. officials to their Egyptian counterparts, and that’s worked,” Mr. Springborg said. “But we buy access; we don’t buy influence. Often our advice is something they need but don’t necessarily take.”
The declining effectiveness of Egypt’s military comes as no surprise to American diplomats and officers, who have been warning superiors in Washington for years.
A secret embassy cable obtained by WikiLeaks in 2010 warned Gen. David H. Petraeus, then the head of the United States Central Command, in December 2008 that under the leadership of Field Marshal Mohamed Tantawi, the country’s defense minister at the time, “The tactical and operational readiness of the Egyptian Armed Forces has decayed.”
More recently, the northern Sinai Peninsula, long a relatively lawless zone, has become a dark reminder of the failure of Egypt’s military and security services to address a new generation of threats, different from any posed by Israeli forces before the 1979 peace accords.
In the seven weeks since Egypt’s military ousted the Islamist president, Mohamed Morsi, the endemic Sinai violence has grown into something like an insurgency, with mysterious gunmen attacking military and police facilities every night.
Some United States lawmakers have sought to restructure the way Egypt uses its military aid. Although the Pentagon has tried unsuccessfully for years to persuade the Egyptian military to shift its purchasing toward counterterrorism and counterinsurgency equipment and training, the breakdown in security in Egypt has brought new attention to the issue.

“The United States should re-evaluate and recalibrate the nature of our assistance relationship with Egypt, taking into account the genuine security threats faced by the country, including terrorism in the region, unrest in the Sinai and protection of the Suez Canal,” said Senator Bob Casey, a Pennsylvania Democrat on the Foreign Relations Committee who visited Egypt and Israel in April and who supports suspending aid to Egypt.
Exasperated American military officials have also watched in dismay as Egypt has failed to invest in its own mechanics and logistics networks, as was originally envisioned, as well as in F-16 pilot training.
Egyptian F-16 pilots receive only a quarter of the flight training hours of American pilots, Mr. Springborg said. Maintenance programs have been left to American contractors.
“It was originally intended that Egypt would develop its own sustainment capability,” Mr. Springborg said. “One of the sad parts of the program is that this didn’t happen.”