Pakistan involved in Mumbai attacks?

So far the Pakistani are denying any involvement in the Mumbai terrorists attacks and are swearing to take action if any of the terrorists are Pakistani-based militants. But here's the problem:

The(Indian) government called a crisis cabinet meeting on Saturday, a day after Indian officials suggested that a militant group with Pakistani ties, Lashkar-e-Taiba, was responsible for the attacks.

If the Indian government finds out Lashkar-e-Taiba is responsible, how will they respond? Since India became a state in 1950 and Pakistan formed their own Muslim government, tensions have been very high, and the smallest thing, I believe, could send the countries into all-out war. Will that happen now? I hope not. But it wouldn't surprise me. And if that happens, it could be a powder keg for a whole lot more...