This week’s stunning advance by the Islamic State of Iraq and the Sham (ISIS) presents some serious questions about the legitimacy of Iraqi security forces (ISF) and Washington’s policy of giving billions in military aid to troubled Middle Eastern governments. Since the fall of Fallujah in early January, the Iraqi military has failed to put down the rising insurgency in the west. Now with the fall of Mosul, Tikrit, and Bayji, it has collapsed completely in the north and much of central Iraq.

It is easy to draw the conclusion that US aid has been a waste and its faith in the Maliki government has been misplaced. While it is true that the Shiite-dominated government has alienated much of the Sunni community, feeding ISIS’s growth, it can also be argued that the Iraqi forces were never fully equipped to provide for their own security.

In December 2011, when the last US forces left Iraq, they took with them much of the vital air assets which enabled security forces to quickly respond to insurgent attacks. This included aircraft for gathering intelligence, transporting troops, providing close air support, launching special operations raids, and conducting MEDEVACs. Since then, Iraq has struggled to make due with a handful of American and Russian-made attack helicopters, and three lightly-armed Cessnas in addition to a small number of trainer and transport aircraft.

Iraq just received its first of 36 F-16 fighter jets requested in 2010 and 24 AT-6 light attack aircraft were approved for sale by the State Department in May. Iraq is also expecting from the US 24 Apache helicopters and 58 unarmed drones, as well as 24 light fighters from Korea, a dozen older light fighters from the Czech military, and several Russian-built attack helicopters.

Meanwhile, Iraqi ground forces have been fairly-well equipped for years with thousands of armored vehicles, a couple hundred tanks, and enough body-armor and small arms to make some Western armies jealous. However, today’s Iraqi military was trained and mentored by a US military which had hundreds of varying types of advanced aircraft in-country that could be called upon when needed. Iraqi soldiers today are not nearly as fortunate.

Iraqi troops cannot be airlifted quickly to threatened areas throughout the country, they cannot rely on medevac helicopters to retrieve their wounded from the battlefield, and they cannot call for immediate close air support if under attack by hordes of ISIS fighters. These are factors which severely hamper morale and are likely contributing to ISF hasty retreat. What advantage the ISF has in armor seems to be evaporating due to poor leadership, sectarianism, and ISIS’s battle-hardened tactics.

Even if the expected aircraft were to arrive tomorrow, it will take time for Iraqi pilots to be trained on them and for Iraqi commanders to learn how to utilize them in an effective way. The exception is the AT-6 light attack aircraft as it is an armed version of the T-6 trainer aircraft the Iraqi air force has been training on for some time. The immediate delivery of these nimble propeller-driven planes, which resemble World War II era fighters, could have some limited effect on ISIS’s advance towards Baghdad.

The AT-6 is actually better suited for the Iraqi air force than its earlier requests for armed drones. They are cheaper, faster, more survivable, better armed, and possesses many of the same optical and infrared sensors found on Predator and Reaper UAVs. They also can operate from dirt runways and share many of the same parts as Iraq’s existing trainer aircraft. Nevertheless, the small number will limit Iraq from having persistent airpower which can monitor ISIS’s movements and respond to calls for air support.

Time is not on Iraq’s side as ISIS’s advance is moving faster than the equipment is being supplied to the country. The one hope Iraq may have is that ISIS is moving so quickly, it could become overstretched and unable to maintain the large, fast-moving force that it has morphed into. ISIS had much more flexibility as an insurgent force. But it will face new strategic and logistical challenges as it seeks to hold the territory it has conquered, while supporting an advancing army.

Patrick Megahan is a research associate for military affairs at the Foundation for Defense of Democracies, where he manage’s MilitaryEdge.org.

This piece original appeared in The Long War Journal’s Threat Matrix.