As things stand India has a strong circumstantial case but it remains circumstantial. Actual evidence of IAF downing a Pakistani F-16 depends on whether or not the US is willing to share evidence of the shoot down. This is unlikely to happen

by Abhijit Iyer-Mitra

In many ways the Air Force's use of the word “irrefutable” evidence doomed it to the furious backlash it has faced in proving through radar intercepts that a Pakistani F-16 was shot down in the aftermath of the Balakot strikes. However as things stand India has a strong circumstantial case but it remains circumstantial. Actual evidence depends on the United States being willing to share evidence of the shoot down. This is unlikely to happen, but it is the micro details of the US end user verification protocol, that this author has been able to obtain from America, that show why the ‘he said, she said’ stories that have been circulating recently have to be taken with a (large) pinch of salt.

Perhaps the most germane detail here is that all Pakistani F-16s are subjected to three kinds of monitoring. First, a 24/7 verification by remote cameras; second, periodic checks of aircraft; and, third, snap inspections. Why each of these checks is resorted to is the key to understanding why the peddled narratives are wrong.

The upgrade of Pakistani F-16 fighters to the Block 50 standard was agreed to in 2005 when the US agreed to sell Pakistan additional F-16s as part of the ‘war on terror’. There were two major roadblocks from the US side to the sale. The first was the fact that Pakistani F-16s had been jerry rigged to carry nuclear bombs. The second was the fact that Pakistan's Chinese manufactured JF-17s had started coming online and would possibly be collocated with the F-16s.

The solution to all these problems was solved thus: First the upgrade was agreed to and in line with Indian concerns and the US' own Nuclear Non-Proliferation Treaty obligations. Those obligations meant that any nuclear delivery capability would have to be removed from the F-16.

The question that arises is what prevents the Pakistanis from jerry-rigging the upgraded F-16s to carry nuclear weapons? Several things actually. The first is the weapons control computer of the upgraded aircraft. A plug-and-play device, what happens is when a bomb is screwed onto the under-wing pylons, much like a USB stick in a computer, the weapons computer automatically recognises the weapon. If the weapon doesn’t match the on-board database of the F-16, the plane does not recognise the bomb, preventing its separation and release during flight. Re-programming the software to recognise unauthorised bombs is possible only if the aircraft’s source codes and software are shared; we know they have not been.

While this solved one problem, the problem of Chinese engineers getting access to Pakistani F-16 remained. This was solved through agreeing to the installation of cameras on all F-16 bases that would monitor the aircraft 24/7. This ensured that Chinese personnel would not be allowed near US aircraft. Second was that during static tests of the electronic emissions of the plane, no Chinese electronic intelligence gathering equipment would be kept in proximity. This had the added benefit that it allowed the US to count the Pakistani inventory at any time of its choice as the F-16s would not be able to remain airborne indefinitely.

This is why Foreign Policy magazine’s report that “unnamed sources” American and Pakistani talking of an aircraft headcount are fundamentally unreliable. However, this raises the question, what are the two remaining physical inspections for. The first: periodic inspections, is to ensure that no data input port or electronics have been tampered with, nor illegal modifications made, whereas the third category: snap inspections, is reserved for when the US has an overwhelming suspicion that some untoward modification or access has happened and is time sensitive. Neither of these physical inspections is to determine numbers.

All of this leads us to ask why the US will not share data on Pakistani aircraft with India.

That’s because US equipment sales come with a two-way guarantee. While Pakistan has the obligation to protect the aircraft from the Chinese and use the planes responsibly, the US has a reciprocal obligation to not divulge details to others. The state of the India-US intelligence sharing agreement is such that the US willingly shares intelligence on China but the standard refrain on Pakistan is ‘that requires a whole different level of political trust between the US and India’. Conspiracy theories on Lockheed Martin's sales prospects in India have nothing to do with it.

To sum up, last week's gossip is not just unreliable it also shows a certain cluelessness on the “unnamed sources” part of the specifics of the US-Pakistan agreements. In short, were back to India having circumstantial evidence and Pakistan having a record of lying.