You know, if you shat on India's corruption problems and leaks in the system, I would agree with you in a heartbeat. The fact is, you look at anything that is kind of necessary (a good aerial protection system when you're in a bad neighborhood) and you froth at your mouth while ignoring something that is completely unnecessary (endemic corruption at all levels).

India can, should and will spend money on defense capabilities because it needs to. The instant NATO and US troops leave Afghanistan, everything may change and Pakistan will once again be able to properly focus on their eastern border. China is already miles ahead of India and poses a threat.

India also needs sanitation.

These two are not related or mutually exclusive. They can and will happen simultaneously because unlike you, even an inept government knows how to allocate budgets and distribute administrative power - here's a sanitation comparison for select states.

I didn't know any of this. I just googled it. You can too.