Who killed Benazir Bhutto? Despite formal admission of responsibility by al-Qaeda, we may never know for sure. In one recent conversation she told me that she had “solemn warnings” from a dozen groups who saw her as the main obstacle to their dream of transforming Pakistan into an “Islamic state”, whatever that means.

I first met Benazir in 1971 when I was a house guest of her father, the Prime Minister Zulfikar Ali Bhutto, in their home town of Larkana, Sind. From the deference Bhutto showed his daughter, it was clear that Benazir, then barely 16, was meant to carry the mantle of the political dynasty that he hoped to start. Only half-jokingly, he referred to her as “my first son”.

In the four decades that followed, which included six years as Prime Minister of Pakistan, five years in solitary confinement, and more than a decade in exile, Benazir proved that she was more than equal to the role that her father, and maybe fate, had scripted for her.

Whoever killed Benazir belonged to one of the nebulae of organisations that have vowed to kill not only those who stand for election but also those who vote. Their slogan is: “From box to box!” This means that, by slipping one's vote into a ballot box, one risks ending up in a coffin.

To people in the West voting in an election might appear banal. In the Muslim world, where the fight today is between democracy and terror, it could be a matter of life and death. Over the past decade, thousands of people, from top politicians to ordinary voters, have been murdered by Islamists in Muslim countries that have held reasonably free elections (Morocco, Algeria, Lebanon, Jordan, Iraq, Turkey, Afghanistan, Bangladesh and Indonesia). Islamist opposition to democracy is based on the claim that allowing men to legislate would be a form of sherk, that is to say associating Man with God, who is the “sole and ultimate legislator”. Man-made law cannot rival God-made Shariah.

Referring to Islam's history, in which the murder of leaders, including three of the first four caliphs, was the surest way of coming to power, the Islamists hope that by assassinating senior politicians they would kill hopes of democracy in the Muslim world.

Since her return home last October after years of exile, Bhutto had been the target of at least three assassination plots. The authorities had warned her to take extra care at mass rallies. She had not listened. She had asked the authorities to provide her with better security equipment, including devices to jam mobile phones. They hadn't listened.

Were the security forces ordered not to protect her? Although the answer is almost certainly no, the question is posed by some Bhutto supporters. How it is answered could affect the way events unfold in the coming months.

Bhutto knew she was risking her life, but reminded everyone that her father, too, “gave his life for democracy in Pakistan”. Despite her education at Oxford and Harvard, she shared the Muslim belief that one's fate is written in advance. If it was her kismet to die this year, there was no point in defying fate. In that sense, the al-Qaeda leaders who take extra care not to risk their lives seem less typically Islamic than Benazir.

“One cannot take part in democratic life from behind walls,” she told me when discussing her hopes for returning as Prime Minister after the general election. “I am not like bin Laden or [Mullah] Omar to hide in a cave. I have to be with my people.”

In our conversations, including e-mail messages, over the past few months, Bhutto had insisted that the elections should go ahead regardless of partisan considerations. She believed that the only way to save Pakistan from a Taliban-style regime was to mobilise the masses through democratic means. For her, dictatorship and terror were political twins that kept each other alive.

“Only the fresh air of democracy can kill the monster [of Islamism],” she liked to say. “When the people are allowed to speak, they will not speak in support of terror.” In that spirit she rejected a call by the former Prime Minister Nawaz Sharif to boycott the elections. What is important now is to fulfil Benazir's wish and make sure that the elections take place.

Although built as an expression of nationhood for Muslims in the Indian subcontinent, Pakistan's legitimacy as a state included other factors. One was an understanding that the new state would be based on the rule of law, and that governments would be chosen and dismissed through elections. Despite several spells of military rule, most Pakistanis remain attached to pluralist politics and multiparty elections.

Since the late 1970s, Islam, the initial source of Pakistan's unity, not to say raison d'être, has become a divisive element. Bhutto's murder took place on the Day of Ghadir, the most important annual festival of Shia Muslims, marking the election of Imam Ali as the Prophet Muhammad's successor 14 centuries ago. Was Bhutto, whose Iranian mother was born Shia, also paying for Pakistan's slide into sectarianism? Islam has become an instrument of oppression in the hands of groups peddling perverted versions of the faith. Pakistanis fight and kill one another over rival interpretations.

By contrast, attachment to pluralist politics represents the principal factor of unity in Pakistan today. Undermine that and you threaten the very legitimacy of the state. The terrorist who killed Benazir believed that Islam is worth killing for. Benazir proved that democracy is worth dying for.

Times Recommends

• In the real world, the public sector must pay
• Playing politics in a land of double Dutch
• Be like the plinth people: not set in stone