As Iran tests ballistic missile, Israel has only a short window in which to strike Iran's nuclear centrifuges
The United States has ordered more ships and warplanes to the Gulf as allied commanders in Washington and London have been quietly shortening the odds on conflict with Iran this summer.
At the weekend, 100 members of the Tehran parliament signed a motion for a new law to empower Iranian naval and Revolutionary Guard units to attack tankers carrying non-Iranian oil and particularly those destined for the United States.
Yesterday, the Revolutionary Guard is reported to have test-fired a ballistic missile capable of striking Israel. The medium-range Shahab-3 missile was fired at a mock target in the Kavir Desert, according to Iran's Al-Alam TV network.
These moves follow the implementation of tougher sanctions against Iran because of its nuclear programme, which most western intelligence agencies now believe is aimed at producing a viable nuclear-tipped ballistic missile soon.
The United States has increased its minesweeper force in the Gulf to eight ships. The UK already has a long-standing patrol of minehunters there. US F-22 Raptor stealth fighter-bombers and F15c bombers have been sent to various bases throughout the region, and two aircraft carrier groups are on standby.
Britain has plans for putting a squadron of Typhoon Eurofighters in the Gulf, either in Qatar or the UAE. An infantry battalion can be moved at short notice. A western alliance led by the US, Britain and France is preparing forces to suppress Iran's coastal anti-aircraft missile batteries and their shore-based anti-ship missiles if there is a sudden flare-up round the Straits of Hormuz.
In the past 48 hours, officials in Washington and London have lessened the likelihood that the Iranian military and Revolutionary Guard will try to shut the Straits of Hormuz. But fears have been growing in the past few weeks that Israel may carry out a pre-emptive strike against Iran's nuclear centrifuges – principally those at Natanz.
Talks with Iran to cease enriching uranium to weapons-grade level have dramatically switched to the slow lane. After making some progress at ministerial level, the pace has dropped. The meeting next week is between technicians only and is expected to make little or no progress.
Israeli politicians, intelligence experts, and senior military officers – speaking both on and off the record – have been explaining over the past few months that Israel perceives it has only a limited "window of opportunity" this summer to mount a military strike against Iran's nuclear facilities.
While targets are relatively easy to identify round Natanz - now the main centre of centrifuges – it is feared that the new facilities being built at Fordow outside the holy city of Qom will be harder to detect and even harder to penetrate.
There, much of the facility and the halls for the centrifuges are being gouged deep into the mountains, hundred of meters underground. Only one of the new bunker-buster bombs capable of generating a small earthquake is likely to have any effect, and these could have unpredictable consequences.
The Israelis say that the attack by computer worms like Stuxnet and Flame in the control systems of the centrifuges at Natanz and in the oil pumping apparatus in southwest Iran have been disruptive – but this will not last. Both are part of a major cyber programme ordered by Barack Obama since the beginning of his presidency – according to revelations by David E Sanger of the New York Times in his new book Confront and Conceal.
"We only have a very limited time left," an Israeli general told me in a background briefing recently. "We have to the end of the summer. Our plans won't be affected by the American presidential election, and even if we get a President Romney it won’t make much difference. It will take up to six months for him to get his team in place – and by then it may be too late."
A senior British military officer, charged with strategic advice to Prime Minister David Cameron, told me recently he thought the Israel-Iran standoff is the top-most strategic concern now in the Middle East, above the conflict in Syria, and the questionable stability of Egypt.
The sense that the Iran nuclear issue is reaching a decision point is now palpable. Sanctions, even before the new round, are biting hard. Oil exports from Iran have gone down 40 per cent since the beginning of the year, from about 2.5 million to 1.5 million barrels a day, and are still falling.
A reaction can be expected soon.