India/Pakistan damn near came to war several years ago and there are, unconfirmed AFAIK, reports of nuclear weapons being released to theater commanders.  Meaning, the world hovered on the brink of a nuclear exchange¹ with the 'hold' being the least stable theater commander.

India has continually repeated they think terrorist attacks in India are being supported and financed by the ISI.  Upon the military and political leadership concluding Pakistan's nuclear arsenal is under, or going to be under, control of the ISI or their political allies a sufficient condition for a pre-emptive First Strike has been met.  

¹ Jargon for a small scale nuclear war.

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre