Last night's carnage was a vivid reminder of the highly dangerous political environment that thr exiled former prime minister re-entered when she stitched together a US-backed power- sharing pact with General Pervez Musharraf.
While it was too early to identify who was responsible, the list of people who would like to kill her is extremely long. Her gender alone would make her a target for some militant Islamists.
Several groups, including pro-Taliban militants, had issued direct threats against Ms Bhutto. The spark for their anger was her open support for the US-led "war on terror" and her warning that if returned to power, she would go after extremists while at the same time pledging to tackle the root causes of public support for extremism in Pakistan, such as poverty and illiteracy. She had also angered Jihadi groups by suggesting that she would allow US forces to operate on Pakistani soil, something President Musharraf may have covertly allowed, but has never admitted.
The obvious source of danger to any Western-backed Pakistani politician lies in the extremist elements in the tribal, lawless provinces along the long porous border between Pakistan and Afghanistan. President Musharraf has already paid a huge political price domestically for his decision to do America's bidding, and send his army in to close this back door to Taliban and al-Qaida-affiliated groups. But there are also elements within the Pakistani political establishment, the security forces (the notorious ISI) and the Pakistani army who may be seeking common cause with the extremists.
Ms Bhutto is unlikely to flinch from accusing her political enemies of complicity in the attack. Indeed in a recent letter to General Musharraf she had already pointed the finger at "certain individuals" within the civilian intelligence sources whom she believed would try to prevent her return. There is a long history of bad blood between her party the PPP, and the Pakistani military. Her father, Zulfikar Ali Bhutto was, executed by the army in 1979.
What happens next is anything but clear. President Musharraf may be tempted to declare martial law. One question must be whether the arrangement between Ms Bhutto and General Musharraf can survive. This marriage of convenience would see the dictator (increasingly hated even by secular opponents) remove his military uniform, while clinging to presidential power, and see her, now enjoying immunity from corruption charges, restored to the role of Prime Minister after democratic elections. Ms Bhutto is hugely popular especially in the south of the country. But it is difficult to imagine how an election campaign can take place if her enemies are prepared to send suicide bombers to kill her.
Given the importance of Pakistan as a Western ally in the "war on terror", the geo-political consequences of the crisis which Pakistan could now be entering are potentially immense.Reuse content