Garvan Walshe was National and International Security Policy Adviser to the Conservative Party until 2008.

Porfirio Diaz, who served seven terms as Mexico’s President, would rue his country’s location as “so far from God and so close to the United States.” Though Ayatollah Khamenei can count on feeling at least as near to God as he finds himself far from the Great Satan, Iran is uncomfortably close to another nuclear power, for whom irredentism is a habit, and that has in the not too distant past controlled Persian territory.

That power, it seems to Tehran, has taken up its traditional, anti-Iranian role, acquiesced in the sanctions regime that has done considerable damage to the Iranian economy, and appears to have persuaded the Supreme Leader to give negotiations over Iran’s nuclear programme a chance. Now that the Kremlin has become a target of sanctions itself, might it be tempted to sabotage those directed at Iran’s nuclear programme? Could the stand-off over Crimea lead Iran to form an entente with Russia, and use that cover to establish the capability for ‘nuclear break-out?’ That is, to get so close to a bomb that she would be able to leave Non-Proliferation Treaty and assemble a device before the dithering West could stop her?

Russia’s job in the international sanctions on Iran has been political, not practical. Moscow  has been called upon to lend legitimacy to Iran’s isolation, while the sanctions effect, which comes from the role the dollar plays in the international trading system, is one the US can impose on its own. If Russian acquiescence might once have been needed to deny some European countries that profited from trade with Iran the excuse that they were merely opposing American unilateralism in the Middle East, Moscow is no longer in a position to back that position up. Were Tehran to attempt to rely on a promise from Sergei Lavrov, Russia’s Foreign Minister, they would find that any cheque drawn on the Bank of Legitimacy (Russian Federation) would be returned stamped “Insufficient Funds.” The European banking system, the only conceivable alternative to the American, would remain closed to Iranian trade.

Far from reassuring Iran, the Crimean crisis should give her reason to worry.  Exhibit A is the ‘Budapest Memorandum’ in which, among other provisions, Kiev gave up its nukes in exchange for security guarantees from the US, the UK, Russia and France. Aside from the absurdity of Russia guaranteeing the security of one of its neighbours or – as any Pole will tell you – the folly of relying on French security guarantees at all, this is simply a reflection of the weakness of international law.  When the stakes might lead to war, treaties with democracies had better be backed by substantial national or political interests. Otherwise, when the going gets tough, the guarantors will reach for their coats, and, adopting their best Ed Miliband voice, mutter: “excuse me, I’d better be going.”

The effect of Western dithering is being felt in the Middle East. However enduring the interests underlying Iran’s nuclear ambitions are (the Shah began the country’s programme, after all), they are seen most clearly as a threat by Israel, and would have been seen as such even had Ahmadinejad never been allowed to threaten to wipe the Jewish state off the map.  Binyamin Netanyahu has for years warned that “it is 1938, and we’re in Munich.” Now he has real example of how Western leaders would react to a crisis for which they were unprepared to bear in mind.

Suppose Israel were to become convinced that Iran had been able, under the cover of negotiations, now gently sabotaged from Moscow, to achieve ‘break-out’ (‘weaponisation is a secondary issue; a primitive device could be loaded onto a truck or ship).  Could any Israeli leader, barring the sudden elevation of Michael Gove to Number 10, be sure they could rely on speedy and decisive Western intervention?

Set aside the obvious differences between Crimea and a nuclear Iran: that Western Europe’s collective memory of Russian expansionism, notwithstanding the invasion of Gerogia in 2008, had dulled; and that Israel has spent years warning of the Iranian threat, whereas Ukraine’s Government had barely assumed office before the first Russian troops seized the Simferopol parliament.  Those differences are real, and matter politically, but Israel’s confidence in Washington’s resolution has fallen too low for them to be of much reassurance.

That’s why Benjamin Netanyahu and Moshe Ya’alon, his defence Minister, were wise explicitly to remind Tehran that a military attack remained very much on the table. The mission would undoubtedly be difficult, though probably not impossible, for Israel to pull off; it would probably only delay Iran’s programme for a few years; it is bound to have other unpredictable consequences. Yet it is equally a fate Iran’s government would prefer to avoid. The optimist-demon on my shoulder would hope those warnings might just give Tehran another reason to do a deal with the West, but his pessimist companion can’t help thinking that Israel’s air force is closer to action than it was before Yanukovich fell.