Take the young people of so many Islamic nations struggling to secure their democratic freedoms. Take large, very powerful armies used to running or controlling the show. Take big pinches of poverty, frustration and religious fanaticism. Spice with visceral violence. Stir briskly – and what have you got? Welcome back to Pakistan. We may be hoping for good things in Cairo and praying for good things in Libya. But good things, ominously enough, don't happen in Jinnah's "Pure State" any longer.

Now here's one especially dismal thing among many others, because it tests principle as well as feeble political resolve. Shahbaz Bhatti, Islamabad's minister for minorities, is assassinated outside his home by four assailants who leave Taliban tracts behind them. Bhatti was a Christian, speaking out for an increasingly oppressed minority and ceaselessly advocating the repeal of Pakistan's blasphemy laws.

But a couple of weeks ago, while the world was watching Cairo and Tripoli, his own prime minister, Yousaf Raza Gilani, quietly abandoned any attempt to repeal Pakistan's blasphemy laws – and the death penalty for breaking them. The battling woman backbencher who'd pushed for abolition retreated. The ministries working on amendments threw them away. Blasphemy, as defined in the statute book by Pakistan's last military dictator but one, remains a capital offence.

So the Christian peasant farm-worker and mother of four, Aasia Bibi, whose case crystallises the whole sorry debacle, remains in prison and in fear for her life. So the governor of Punjab province, Salmaan Taseer, murdered by his own bodyguard for speaking out, remains unavenged. Remember how 90 lawyers put their hands up and volunteered to defend Taseer's killer for free. Remember how the elected government of the Pakistan's People Party, the party Taseer belonged to, did nothing but mumble. Remember how it promised reform then shuffled away. Don't forget, then, that Shahbaz Bhatti's murder comes as a direct consequence of the pusillanimity of an elected government.

It is the supposed bulwark of freedom, of democracy, of the supreme rule of law that we all like to hymn at suitably euphoric moments. But, at a time of true test, President Zardari and his ministers slide away.

Why does this debacle, in its way, seem so much worse than Islamabad's lurching efforts to subdue the Taliban and give the west the help it craves in the battle against terrorism? Because the issues are clear enough. Because there's no need to get tangled in Afghan blame games, nor rows about CIA agents and American imperialism. Because this crisis is all about Pakistan.

Zardari's PPP is the supposed torch-carrier of enlightenment and reform here: a force for change amid a gaggle of parties in thrall to religious zealotry, and a foe of the army's tendency to play Islamic cards itself when its hegemony is threatened. There's no possible doubt which side it ought to be on. There isn't even much doubt which side it took as the case of Aasia Bibi developed. But now frailty leads its leaders by the nose.

Why? Of course you can blame them for personal fear: Bhatti's death underlines the grim message of Taseer. Speak out and you may not live long. Taliban extremism claims more victims every day. But the real problem is that, across Pakistan, ordinary people taught by ordinary mullahs to reach extraordinary conclusions, have come to side with the blasphemy laws as well. They don't want repeal. They want matters to rest as they are. Crude democracy, in a way, wants Aasia Bibi punished – and so for Pakistan's 4% of Christians to live in constant fear. There are thousands of relatively liberal, more educated voices in play; but there are many more millions who see nothing wrong as lawyers queue to plead their sad case. A sentence out of place means death: killing those who find this law grotesque seems to mean instant heroism.

Who'll draw a line and turn the tide? No president, present or future, you can see. Not a feeble, flailing Zardari. Not his old adversary, Nawaz Sharif and his Muslim League. Not some general waiting in the wings. The difficulty is that there is no one, and no concerted body of opinion, who can join, let alone hope to win, this debate for what may come to symbolise the destiny of Pakistan. For tolerance, for restraint, for the ability to live side by side in a truly free world? If Cairo adds a spoonful of hope, Lahore, Karachi and Islamabad bring only the recipes of despair.