Washington, Dec 3: US-sponsored war games that simulate capturing Pakistan’s nuclear weapons to prevent them from falling into wrong hands are having a negative impact, experts have said.

The Washington Post carried a detailed report on such exercises, pointing out that the all such games came to the same conclusion: Pakistan’s cooperation -- particularly that of its military – was crucial.

The US Government has conducted several such games in recent years, examining various options and scenarios for Pakistan’s nuclear weapons, the paper said.

How many troops might be required for a military intervention in Pakistan? Could Pakistani nuclear bunkers be isolated by saturating the surrounding areas with tens of thousands of high-powered mines, dropped from the air and packed with anti-tank and anti-personnel munitions? Or might such a move only worsen the security of Pakistan’s arsenal?

"Our best bet to secure Pakistan’s nuclear forces would be in a cooperative mode with the Pakistani military, not an adversarial one," Scott Sagan, a Stanford University expert on counter-proliferation said.

Feroz Khan, a retired brigadier who until 2001 was the second-ranking officer in the Pakistani Strategic Plans Division, warned that holding war games, exploring the possibility of capturing Pakistan’s nuclear weapons might worsen the situation.

He said such exercises antagonised Pakistanis and might encourage the government in Islamabad to take counter-measures.

"You might just want to remember Desert One," Khan added, referring to the botched US mission to rescue American hostages in Iran in 1980.

As a result of US government studies of the nuclear issue, Pakistani officials had come to believe a US intervention "is a real threat now," Khan said.

The Pakistani military almost certainly had taken steps to forestall such a raid such as creating phony bunkers that contain dummy nuclear warheads, he said.

He estimated that Pakistan’s current arsenal now contained about 80 to 120 genuine warheads, roughly double the figure usually cited by outside experts.

Zia Mian, a Princeton University physicist and expert on nuclear proliferation in South Asia, agreed with Khan’s views.

Among other negative repercussions, he predicted that any US effort to secure Pakistan’s nuclear arsenal "would really increase anti-Americanism."

The Paper quoted US intelligence officials and counter-proliferation experts as saying that an internal break up could allow religious extremists in Pakistan to grab some of the nuclear arsenal, not necessarily to use them but to wield them as a symbol of authority.

One participant in last year’s game told the Post that there were no palatable ways to forcibly ensure the security of Pakistan’s nuclear weapons -- and that even studying scenarios for intervention could worsen the risks by undermining US-Pakistani cooperation.

Sagan argued that mere contemplation of a US intervention might actually increase the chances of terrorists acquiring a nuclear warhead.

He said that in a crisis, the Pakistan Government might begin to move its nuclear weapons from secure, but known sites to more secret but less-secure locations.

In such locations, Sagan concluded, the weapons would be more vulnerable to capture by bad actors. "It ironically increases the likelihood of terrorist seizure," said Sagan, who in the past had advised the Pentagon on nuclear strategy.

He noted that Pakistan moved some of its arsenal in September 2001, when it feared it might be attacked.

But Khan said that Sagan’s fears were misplaced. The weapons "are in secure bunkers, with multiple levels of security, and active