Triumph is often twinned with tragedy in Pakistan, and former Prime Minister Benazir Bhutto's return home last week was no exception. What began as a jubilant homecoming for this twice-deposed leader ended with one of the worst terrorist attacks ever to occur on Pakistani soil. As Bhutto rode through Karachi, Pakistan's largest city, greeting hundreds of thousands of supporters, a suicide bomber blew himself up in front of her vehicle, killing at least 136 people and injuring hundreds.

Bhutto's political life has always been tumultuous. I first met her in far less violent days, more than a decade ago, after she'd been removed for the second time as Pakistan's prime minister, accused of corruption and misrule. Back then, Pakistani politics was known mostly for its mud-slingingand mutual retribution. I followed Bhutto as she campaigned in one huge rally after another, trying to regain power in Pakistan's 1997 national elections. She and her Pakistan People's Party (PPP) eventually got trounced by her rival, Nawaz Sharif, and Bhutto left Pakistan two years later to avoid facing what she called politically motivated corruption charges, which came with a hefty prison sentence.

In those days, Bhutto's main grievance involved the "slander" about corruption and misrule to which she felt subjected by her enemies. In retrospect, this seems almost quaint. Pakistan has changed a lot during Bhutto's eight years away. Suicide bombings were unheard of when she left the country in 1999; now, as she knows firsthand, they happen with horrific frequency. And the Taliban — a movement she helped cultivate within Pakistan's borders in the mid-1990s, something she's since conceded was a fatal error — have now turned on Pakistan itself, perhaps even on her. (No one has yet claimed responsibility for the suicide attack, although Taliban and other extremist leaders had threatened to kill her earlier.)

Bhutto's political career is the stuff of legend. She's the daughter of a martyred leader, and as a young woman, she suffered for years in prison and exile until she became prime minister in 1988, the first woman ever to be elected leader of a Muslim country. She defined herself early on by her opposition to military rulers — one of whom, Gen. Muhammad Zia ul-Haq, overthrew and executed her father, Zulfikar Ali Bhutto, Pakistan's most influential prime minister. But over the years, she became a divisive figure and twice squandered Pakistani voters' goodwill with her inability to govern effectively. Having lost credibility in her own country, the Harvard- and Oxford-educated Bhutto did her best to present herself to the rest of the world as a pro-Western, progressive voice of reason, the best alternative in a sea of Islamist militants and army generals. She's said she's learned many lessons from her political past that will help her bring change and democratic rule to her country.

She never gave up on coming home. To do that, she struck a controversial deal with a general she's criticized in the past, Pervez Musharraf, Pakistan's increasingly unpopular president and army chief.

They both held their noses and agreed — with U.S. support — to a power-sharing arrangement in which he'll drop all the old corruption charges against her, in exchange for her party's support for his re-election as president. Dropping the curruption charges paves the way for her to run for prime minister in elections scheduled for January. The common ground they share is a stated commitment to fighting terrorism and strengthening Pakistan's moderate majority.

But even before last week's carnage, there were serious questions about January's elections and Pakistan's future. For starters, Pakistan's constitution prohibits third terms for prime ministers.

Pakistan's high court may prohibit Musharraf from dropping the corruption charges against Bhutto. It may even invalidate his current role as Pakistan's president. Some of Bhutto's political rivals in Pakistan still have Musharraf's ear. Beyond this, critics point out that Bhutto's strange-bedfellows arrangement with Musharraf has weakened the very democratic credentials by which she defines herself — and sweeping away her corruption charges undermines the notions of accountability that are so important in a democracy.

The circumstances surrounding Bhutto's return now raise important questions about her own vulnerability, and indeed the instability of Pakistan's entire political process. It's impossible to predict how things will be resolved or not in the weeks to come, but the way in which Bhutto, Musharraf and some of Pakistan's other politicians work together or fail to will almost certainly define the outcome.

A month after Bhutto's defeat at the polls in 1997, I visited her at her home in Karachi. She declared then that she never wanted to be prime minister again. Bhutto said she wouldn't want the job "even if someone walks through that door with a golden platter and says, 'Here's a letter appointing you prime minister.' " In the intervening years, she's obviously reassessed that career decision. Now, she does want to be Pakistan's prime minister again and many see her alliance with Musharraf as the country's best hope. After Thursday's violent homecoming, it's clear she may have to fight for her life to succeed.

Hannah Bloch covered Pakistan and Afghanistan for Time magazine from 1996 to 2002. She wrote this commentary for The Advertiser.