Why won't Obama take on the mullahs?

IRAN is getting away with murder while the White House looks the other way.

The US military discovered a "significant shipment" of arms from Iran to Afghanistan, the Chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, revealed on March 31.

Responding to a question at a press conference in Kabul, Mullen, the US's highest-ranking uniformed officer, said he was disturbed by Iran's growing influence in Afghanistan. "I was advised last night about a significant shipment of weapons, from Iran into Kandahar not too long ago, for example."

How significant was the shipment? "I was taken aback," the military chief said.

Any shipment of arms from Iran to Afghanistan is worrying. But the timing of this one, shortly before the fighting from the US troop surge moves to Kandahar, is particularly troubling.

Mullen said the Iranians' "desire to be influential" was increasing. A week earlier, CNN reported that Tehran was training Taliban fighters in Iran.

Although support for the Taliban from Iran is growing, it is not new. CBS reported last year that Tehran had stepped up shipments of explosively formed penetrators and armour-piercing bombs. "More worrying still," it said, "US intelligence believes Iran is supplying surface-to-air missiles to the Taliban -- the very same weapon the US supplied to the Afghan resistance to bring down the Russians."

The level of Iranian support for the Afghan insurgency does not yet match the crucial support Iran has provided to the Shia militias and Sunni militant groups in Iraq. Iran's aggressive and deadly activity in Afghanistan is growing, and its support for the insurgents in Iraq continues.

Iran is the only nation that is actively supporting the forces fighting the US army in both places. This war, or proxy war, is not led by rogue elements -- it is directed by the Iranian government and approved at the highest levels. It is Tehran's policy.

This should not be surprising. The US has designated Iran for years as the world's leading state sponsor of terrorism. Tehran does not hide its support for Hamas in Gaza and Hezbollah in Lebanon. And it has long harboured senior al-Qa'ida leaders.

All of which provokes two questions: why doesn't Barack Obama talk about Iran and terrorism? And why hasn't the US President, so quick to condemn Israeli construction of Jewish settlements, ever rebuked Iran for arming and training those who are killing US troops?

When world leaders met in Washington for a summit on nuclear terrorism and proliferation, Obama told them nuclear terrorism was "one of the greatest threats to global security".

Iran -- an active sponsor of terror now racing toward nuclear weapons -- should have dominated the agenda. It didn't.

Clearly, talking about Iran and terrorism complicates Obama's diplomacy. Since the start of his administration, the President has chosen to believe Iran may voluntarily give up its nuclear weapons program. To a great extent, his approach depends on maintaining that assumption.

It is hard to understand how Iran, in the context of its covert war with the US, will suddenly become a good faith negotiating partner on its nuclear program. And it becomes more difficult to pretend that the Iranian leaders responsible for this aggression might willingly abandon their quest for a weapon that would make their nation into a regional superpower.

For the past two months, administration officials have told reporters on background that China and Russia will eventually support sanctions against Iran. And each time, a representative of the Russians or the Chinese downplayed the claim and raised questions about the effectiveness or desirability of tough sanctions. Or both. But when reporters from The New York Times tried to get Obama to embrace Hillary Clinton's description of the sanctions his administration was pursuing as "crippling", he baulked.

So the Obama administration, after allowing the mullahs to miss deadline after deadline while it waited for a compromise, is no longer pushing for tough sanctions. And Iran, its centrifuges spinning, continues to supply those who target US forces. This is not going to end well.