The first possibility can be ruled out as of today. In the eventuality of his capture, the security forces responsible for his capture would know for certain.
In the eventuality of his death in a ground encounter or an air strike, the proof will come in the form of the recovery of the dead body or from the interrogation of anyone of his associates captured during the encounter or by monitoring the communications of the survivors of the encounter or air strike.
Where the dead body is not recovered, the intelligence agencies will be able to establish his death through the other means (interrogation of associates or communications interception) with two-thirds certaintly, but not a hundred per cent certainty.
If he dies a natural death, the indicators would come either from the doctor or doctors, who had treated him or from one of his associates, who was with him at the time of his death -- if any of them could be captured by the security forces -- or from his relatives in Saudi Arabia.
One had seen in Jammu and Kashmir, where many Pakistani and other foreign jihadi terrorists operate, that the first indicator of the death of any foreign terrorist due to natural causes came from his home country when the local intelligence received information about the relatives holding a religious function to mark the death of the terrorist.
Generally, reliable information about such religious functions being held in the home country are an important indicator of the death of the terrorist in a foreign land. Instances, where the relatives are told by a terrorist organisation to hold false religious functions to mislead the intelligence agencies and security forces are rare, but cannot be ruled out.
Bin Laden's health had been fragile for some years. He suffered from a kidney infection while he was living in Khartoum before 1996. This ultimately affected the performance of his kidneys after he shifted to Afghanistan in 1996. Though it was not life-threatening, he had to undergo periodic dialysis in a Pakistani military hospital at Peshawar.
He suffered a splinter injury at the Tora Bora encounter in Afghanistan with the US security forces. This affected his speech and partially paralysed one of his limbs. In the beginning of 2002, after he had escaped into Pakistan from Afghanistan, the late Mufti Nizamuddin Shamzai of the Binori madrasa of Karachi, who was very close to bin Laden and Pakistan's Inter-Services Intelligence, had him shifted to the Binori complex with the ISI's permission. He was being treated there till August 2002. He recovered his speech and the paralysis caused by the splinter was reportedly cured.
When bin Laden was in the Binori complex, Khalid Sheikh Mohammad, who had orchestrated the 9/11 terrorist strikes in the US, and Ramzi Binalshibh of Al Qaeda were also living clandestinely in Karachi, but at different places with the ISI's knowledge and connivance.
The US intelligence, which apparently discovered their presence, stepped up its search for them. This led to Ramzi's capture, but Mohammed escaped to Quetta and from there he went to Rawalpindi where he was finally arrested in March, 2003, in the house of a woman functionary of the Jamaat-e-Islami.
In August 2002, reports about bin Laden's presence in Binori and his medical treatment there stopped coming in. Subsequent enquiries indicated that he had moved back to the tribal areas of Pakistan. He became active again recording many video and audo messages for telecast by Al Jazeera and other television channels and radio stations. He remained active till the eve of the US presidential election in November 2004, and then became incommunicado. There were no video or audio messages for 13 months.
There were reports of a deterioration in his health due to the kidney condition in 2005. During the Friday prayers in some mosques of the Federally-Administered Tribal Areas in Pakistan, the mullahs started reciting prayers for the good health of Osama's son. This gave rise to strong speculation that bin Laden had died of a multiple organ failure arising from his renal problem.
Suddenly, his audio messages started surfacing again from January 19, 2006, but there were no video messages. Thus, his voice became the only indicator of his being alive. Since July, there has been no audio message either of current origin. Old pre-July messages of his continue to circulate. Cut and paste versions of his pre-November 2004 video messages also continue to circulate.
The speculation about his being alive or dead has again revived following the publication by L'Est Republicain, a French regional newspaper, on September 23, of extracts from a document dated September 21, of the French external intelligence agency stating that bin Laden died in Pakistani territory on August 23, due to complications, including paralysis, arising after a severe attack of typhoid.
The information has been attributed to Saudi intelligence sources, who reportedly came to know of it on September 4. The Saudi services are reportedly trying to verify the information.
The fact that the French government has reportedly ordered an enquiry into how the newspaper came into possession of a classified document indicates that the document is probably genuine, but not necessarily the information contained in the document. One does not know how the Saudi services came to know of this information.
If bin Laden had died in Pakistani territory while undergoing medical treatment there should be doctors in Pakistan who must have treated him. In the past, the Pakistani authorities had detained a doctor from Lahore, who had returned from the US after working for some years there, on a charge of providing medical assistance to Al Qaeda cadres injured in Afghanistan. He was ultimately released for want of prosecutable evidence against him.
The questioning of this doctor and other doctors, who were in the past suspected or known to have treated ill or injured Al Qaeda and Taliban cadres might provide a useful lead.
It is possible that the Saudi intelligence services picked up the information from bin Laden's relatives in Saudi Arabia, who would know if he is dead. If the Saudi intelligence services had told the French about it, they would have definitely alerted the ISI and US intelligence too.
The policy of Western intelligence agencies has been to presume that bin Laden is alive and kicking until he is proved to be dead. That proof is yet to come. Any evidence coming from his relatives in Saudi Arabia or from the doctors or others in Pakistan will be tentative. The only conclusive evidence will be a statement from Al Qaeda admitting his death.