Pervez Musharraf's departure from the presidency is unlikely to have a significant impact on how Pakistan's nuclear weapons are controlled.
Experts say a 10-member committee, and not just the president, makes decisions on how to use them and only a complete meltdown in governance — still a distant prospect in Pakistan — could put the atomic bomb in the hands of extremists.
"Pakistan's nuclear assets are not one man's property," said Maria Sultan, a defense analyst and director at the London-based South Asian Strategic Stability Institute.
"Any (political) transition in Pakistan will have no effect on Pakistan's nuclear assets because it has a very strong custodial control."
Facilities are tightly guarded
The committee, known as the National Command Authority, is served by a military-dominated organization with thousands of security forces and intelligence agents whose personnel are closely screened. The nuclear facilities are tightly guarded.
"The reality is that Pakistan's government exists on different levels. One of the levels it exists and works at is in the control of its nuclear weapons," said Patrick Cronin, director of the Institute for National Strategic Studies at the National Defense University in Washington.
"Where it does not work is in providing effective services, jobs, education and health that people need."
Although one of Asia's poorer nations, Pakistan became the Islamic world's first atomic power through a combination of guile, determination and illegal procurement of technology on the international black market. It tested the bomb in 1998, a year before Musharraf took power, in response to a similar test by its historic rival India.
The prospect of a nuclear conflagration on the subcontinent has eased in recent years as Pakistan and India have talked peace. But political volatility in Pakistan, combined with the revelation in 2004 that its chief scientist Abdul Qadeer Khan had shared nuclear know-how and technology with Iran, North Korea and Libya, heightened concern over how safe the weapons and nuclear infrastructure were.
Those fears have persisted as al-Qaida and Taliban militants have gained a firm foothold along the lawless northwestern frontier with Afghanistan. Pakistan also has struggled to dispel suspicions that elements in its intelligence services have extremist sympathies.
Thousands of troops involved in effort
Early this year, after Pakistan was assailed by a wave of suicide attacks — including one that killed former prime minister Benazir Bhutto — the Musharraf-led administration went out of its way to reassure the international community that its nuclear assets remained safe.
Khalid Kidwai, head of the Strategic Plans Division which handles Pakistan's nuclear arsenal, told journalists that Pakistan uses 10,000 soldiers to keep the weapons safe and has received up to $10 million in U.S. assistance to enhance security.
He said there was "no conceivable scenario" in which al-Qaida or Taliban militants would take power, and asserted that Pakistan's nuclear weapons, fissile material and infrastructure were "absolutely safe and secure."
The military-run Strategic Plans Division was instituted by Musharraf.
While little is expected to change in how it functions after his resignation from the presidency on Monday, the chairmanship of the 10-member National Command Authority that would make the final decision on the deployment or use of weapons will now transfer to acting president Mohammedmian Soomro, the chairman of the upper house of parliament.
That high-powered committee also includes the chiefs of the army, navy and air force, the prime minister, several Cabinet ministers and Kidwai, himself a retired general.
Decision to use weapons by consensus
Kidwai said in January that any decision to use the weapons would be reached "hopefully by consensus but at least by majority." The decision would be conveyed to the Strategic Plans Division and then through the military chain of command.
"Pakistan's nuclear arsenal is in the hands of the army and the army is not changing hands, so whatever the situation was before is largely what it will continue to be," said Teresita Schaffer, director of the South Asia Program at the Washington-based Center for Strategic and International Studies.
Talat Masood, a retired Pakistani general, said the civilian government elected in February may push to transfer the chairmanship of the command authority from the president to the prime minister, Yousaf Raza Gilani, to reflect the shift in power away from the presidency. The premier currently serves as its vice chairman.
The military, which has distanced itself from politics since Musharraf ceded command of the armed forces in November, would not necessarily oppose that. The powers of the presidency may soon be diluted — if the government follows through on plans to amend the constitution — reverting it to a largely ceremonial position.
While experts say Pakistan's nuclear assets will stay in safe hands for now, fears persist about the potential for an Islamist takeover.
"If Pakistan becomes a more fragile and even failing state, then the nuclear assets will be everybody's problem internationally. The best way to prevent that from happening is in strengthening the new government's ability to govern," Cronin said.