yup, any one can start a war but how it ends is what matters. Kargil was a good example of what happened. Pakistan can be the first to use it but they wont be the last one.What this means is the very last move Pak can make is start a nuclear war, but India has the capacity to end the war.
pakistan has tried to take over kashmir by staging 3 to 4 wars since independence. Even after having nuclear weapons they are still trying to do the same but with no success. If pakistan had the confidence or capacity to use nukes they would have already done so.