The negotiations between Iran and the West have not yet produced a deal. At the same time the BBC’s Mark Urban, a defence correspondent, has unearthed a worrying connection between Iran moving towards the nuclear bomb threshold and a Saudi Arabian decision to produce a nuclear bomb with Pakistani help. “Saudi Arabia has invested in Pakistani nuclear weapons’ projects and believes it could obtain nuclear bombs at will”, he says.

This meshes with what I wrote in my column 20 years ago that the only way to explain Saudi Arabia’s purchase from China of CSS-2 ballistic missiles was that it was preparing to develop a nuclear arsenal if one day the security situation demanded it.

The Chinese missiles have a capacity to carry nuclear weapons. They are too inaccurate to be of use as conventional weapons. They are an insurance against Iran developing nuclear weapons and also have the additional purpose of providing a balance to Israel’s armoury of some 200 nuclear weapons.

The Saudis have recently completed a new base with missile launch rails aligned with Iran and Israel. According to the BBC, there is some evidence that the Pakistanis might have already set aside a number of warheads for delivery to Saudi Arabia.

Last month Amos Yadlin, a former head of Israeli military intelligence, told a conference that if Iran got the bomb “the Saudis will not wait one month. They have already paid for the bomb [by funding its early development]. They will go to Pakistan and bring back what they need to bring.”

Four years’ ago King Abdullah of Saudi Arabia warned a visiting American envoy, Dennis Ross, that if Iran crossed the threshold “we will get nuclear weapons”. Gary Samore, who was Barack Obama’s counter-proliferation advisor until last year, told the BBC, “I do think the Saudis believe that they have some understanding with Pakistan that, in extremis, they would have claim to acquire nuclear weapons”.

In a semi-official book, “Eating The Grass”, Major General Feroz Hassan Khan acknowledged that “Saudi Arabia provided generous financial to Pakistan that enabled the nuclear program to continue.”

The Saudis recently showed how estranged they are from US and European Union policies. In an unprecedented protest they refused to take up their Security Council seat which was their’s for the taking. The softening of the US negotiating position vis a vis Iran, in the Saudi elite’s thinking, is a step backwards and would allow the Iranians to continue to prepare to make a bomb.

For years the Saudis have felt they and the US have been moving apart. They were against the toppling of Iraq dictator, Saddam Hussein. They are giving financial support to the new military regime in Egypt, putting them at odds with the US which has reduced some of its aid. They feel the US is becoming too easygoing with Iran. They have been deeply unhappy about US policy towards Israel. Indeed, US Secretary of State, John Kerry’s no-holds-barred lecturing last week of Israeli prime minister, Benjamin Netanyahu, on his settlement policy on Arab land, may have been partly to placate Saudi Arabia as the US prepared for substantive negotiations with Iran.

The Saudis also point out they are a member in good standing of the Nuclear Non-Proliferation Treaty (NPT) and have argued for years that there should be a Middle East Nuclear-Free Zone, as there is in Latin America. (Brazil and Argentina shut down their nuclear bomb plans.) The US has never supported this, making nonsense of its adherence to the NPT.

If the Saudis do get its hands on Pakistani nukes the US would have no choice but to punish Pakistan with severe sanctions. But the Saudis would then step in with financial assistance.

The Pakistani Foreign Ministry describes the above as “speculative, mischievous and baseless”. Certainly there would be many within the Pakistan establishment, including the army, who would argue for Pakistan to hold back from helping the Saudis. I suspect the respected Sartaj Aziz, Prime Minister Nawaz Sharif’s foreign policy advisor, with whom I have discussed nuclear issues, would be one of these.

These are the complicated and convoluted shifting sands in the nuclear “game”. Can’t the Saudis be persuaded that it is in their own interest for the West to forge a deal with Iran?

The fact is there are good reasons for not taking any risks in securing an Iranian agreement by pitching US and EU demands too high. The US and the EU have no choice, whatever Saudi Arabia says about a likely deal being ineffective and whatever plans it has to put warheads on its rockets, but to be flexible in their negotiations with Iran.