Why not to break relations with pakistan after mumbai attack?

They say diplomaticaly it is not good for india to stop peace talks with pakistan even after mumbai terrorist attack. What peace talks are they talking about?
They say america will not support india if india stops peace talks because america needs pakistan’s help because of situation in afganistaan. Why you need america to support you? If america is that good it will support in right cause but if they are not supporting right things then why do we need its support.
They say relation with china will get bitter if india react strongly against pakistan. When were relations were “sweet” with china. Why to care about them.
If these countries dont support a countries’s efforts to protect its people, why to think about them?