Tony Blair confirmed last week that bombs used to kill eight British soldiers in Iraq were a type used by Iran's Islamic Revolutionary Guard Corps and groups that it supports in Lebanon.
His words were circumspect, but the point was clear: London considers Tehran responsible for killing British troops in Iraq. Blair's accusations confirm that the British-secured zone, once praised as a triumph for the 'softly-softly' approach, is a model no more. In recent weeks death squads have kidnapped and murdered journalists, most famously Steven Vincent, an American freelance writer who had warned of Iranian infiltration of the police. Dozens of Iraqis have fallen victim to Iranian-backed militias.
It did not have to be this way. The Iranian challenge in Iraq has long been apparent. In January 2004, Lebanese Hizbollah opened offices across southern Iraq. In the centre of Basra, Lebanese Hizbollah flags flew from an annexe to the Supreme Council for Islamic Revolution in Iraq headquarters.
In exchange for quiet, British officials have turned a blind eye to the Iranian challenge. When Shia militias turned away from schools girls not conforming to Muslim standards of dress, British forces did nothing to guarantee them a right to education. When young gangs plastered the University of Basra with posters of Ayatollah Ruhollah Khomeini, British officials remained silent. An official assessment following Muqtada al-Sadr's uprising in April 2004 blamed a British political officer in al-Kut for 'intentionally toning down' reports of [Shia] insurgent activity'. In Amara, British officials transferred the Baath party headquarters to the Badr Corps; many locals wanted to use it as a health clinic instead. The Iranian-trained militia festooned their new headquarters with anti-coalition slogans. British troops refused to be provoked.
For terrorists and their sponsors, British restraint is assumed. There is little fear of military reprisal. A major factor behind the Iranian government's willingness to murder British troops has been the impotence and naivety of UK diplomacy.
It has become conventional wisdom among the foreign policy elite that military force is never appropriate. The outbreak of the Iraqi insurgency and the fumbled reconstruction have reinforced anti-war sentiment among the chattering classes. If only President Bush had listened to the international community and allowed United Nations inspectors to finish their job, they say, war might have been averted.
War should always be the last resort. But a credible military threat is sometimes necessary to maintain peace. In the case of Iran, British cabinet officials have undercut diplomacy. As tension between Washington and Iran escalated last month, for example, Foreign Secretary Jack Straw was asked about the possibility of military action. 'US Presidents always say all options are open. But it is not on the table, it is not on the agenda. I happen to think it is inconceivable,' he told the BBC on 28 September. Al-Jazeera's headline for this was: 'No military action against Iran.'
Straw may have wanted to reinforce the notion that London remained committed to diplomacy, playing to a British public conditioned to view the American President as a reckless cowboy and religious nut. But his words were interpreted in Tehran as weakness.
Engagement alone can backfire. Between 2000 and 2005, trade between Iran and the European Union has almost tripled. During the same period, it doubled its number of executions and spent several billion dollars on its nuclear programme.
Iranian diplomats may be sincere. They may have impressed Straw. But the Islamic republic's structure leaves them impotent. Only the Supreme Leader, the Revolutionary Guards, and the Intelligence Ministry wield power. It is no accident that Iran's envoy to Iraq was not from the Iranian Foreign Ministry, but from the division of the Revolutionary Guards charged with the export of revolution.
Diplomacy backed by the threat of military force can be a winning combination. What little success the negotiations regarding Iran's nuclear intentions have had are due not only to European carrots, but also American sticks.
Iran is not alone in this. Examining Libyan leader Muammar Gadaffi's decision to settle his differences with London and Washington, US columnist Charles Krauthammer suggested it was no coincidence that 'Gadaffi's first message to Britain, the principal US war ally and conduit to White House war counsels, occur[red] just days before the invasion of Iraq.
'And his final capitulation to US-British terms occur[red] just five days after Saddam Hussein is fished out of a rathole.' Had Straw assured Gadaffi he need never fear military reprisal, the Libyan leader would today be nearing completion of his nuclear bomb. Might matters.
If democracy prevails in Iraq, the Iranian leadership understands that 70 million Iranians will clamour for the same rights. Iraq's success poses an existential challenge. While Iran's youth crave Western pop, fashion and freedom, ideology dominates the Islamic republic's leadership. Khomeini's constitution enshrines theocracy and the export of revolution.
No amount of reform can change that. And no amount of engagement can ameliorate its challenge.
The best the West can hope for is containment. Diplomacy can repulse the Iranian challenge in Iraq, but nice words alone are insufficient. Deals must be obeyed and promises kept. Sometimes that takes a willingness to use force.
Armies, not words, are a diplomat's most potent tool.
Michael Rubin, a resident scholar at the American Enterprise Institute in Washington, is the editor of the Middle East Quarterly