Chips are bad. Planes are not.
The United States controls exports of microprocessors (yes, microprocessors) to defence equipment manufacturers in India. One businessman was jailed for illegally selling 500 chips to India. The logic behind such export controls is to prevent India from developing and using such things like fighter aircraft, which ostensibly would be a Bad Thing for US interests.
And then you note that the US is keen to sell state-of-the-art F-16 and F/A-18 aircraft to the Indian Air Force, and that’s not a Bad Thing at all.
It’s not about arms control. It’s good old protectionism. And what if the India simply decides to buy Russian or European jets instead? What does that do for US interests?
Update: Oh, and by the way, did you know that Apple forbids you from using iTunes 7 software to develop, design, manufacture or produce weapons of mass destruction? Does that mean you can use iTunes to test them? [Via New Scientist blog]