India expects Pakistan to believe the proof and then act on it effectively. India's prime minister sets forth this attitude very clearly:
Pakistani authorities "must have had" a hand in the deadly Mumbai siege, India's prime minister said Tuesday, stopping just short of directly accusing Islamabad of aiding the gunmen.
Prime Minister Manmohan Singh repeated India's allegations that the attack was carried out by the Pakistan-based militant group Lashkar-e-Taiba. But in his most forceful speech since the November attacks, he also said "there is enough evidence to show that, given the sophistication and military precision of the attack, it must have had the support of some official agencies in Pakistan."
And just as clearly, Pakistan will find no level of proof sufficient to act resolutely against jihadis inside Pakistan:
Pakistani authorities dismissed the accusations as "a propaganda offensive," and said charges that state agencies were involved in the attacks were "unwarranted and unacceptable."
"India must refrain from hostile propaganda, and must not whip up tensions," said a Foreign Ministry statement. "Pakistan emphatically rejects the unfortunate allegations."
And both sides accuse the other of whipping up war hysteria.
If just one side believes the other is preparing to initiate a war, very bad things can happen.