Younger readers may not have heard of the Phantom F-4, a fighter-bomber that entered service in 1960. It is back in the news because Iran’s air force used some of these museum pieces to bomb ISIL targets in Iraq.
These planes were bought during the Shah’s era but since the 1979 revolution, US sanctions have meant every spare part has been bought through covert means or reverse-engineered in Iranian factories.
But what has caught the attention of the world is that these raids are the clearest sign yet of a politically toxic alliance of convenience between the US and Iran against ISIL. The public would not have known that Iran and the US were launching air strikes at the same time if not for Al Jazeera broadcasting footage of a bomber identified as being an Iranian Phantom.
The US Air Force, which sees everything that moves in the skies over Iraq, clearly knew about these bombing runs. But when Pentagon spokesman Rear Admiral John Kirby was asked about reports of the Iranian strikes, he tied himself in knots, or at least double negatives: “I have no reason to believe that they’re not true.”
When reporters asked if there was coordination to prevent the American and Iranian aircraft from bumping into each other, he replied that “nothing has changed about our policy of not coordinating military activity with the Iranians”.
As for Tehran, the first reaction to their cross-border strikes was to claim nothing of the sort had happened. ISIL is a terrorist problem, they claim, that was created by the US, so the Americans should sort it out themselves. Later, it emerged that Iran has a 40km buffer zone inside the Iraqi border where, by agreement with the Baghdad government, it can attack ISIL forces.
That old enemies may come together to fight a common foe is a familiar story. But these bombing missions against ISIL reflect an alliance that dare not speak its name either in Washington or Tehran.
Thus, the Pentagon spokesman has to skip over political tripwires. The first of these is the bitter rift between the White House and Congress. Washington politics is so poisonous that the legislature will stop at almost nothing to trip up the president. This general rule is applied with particular severity when it comes to Iran.
Mr Obama sees the chance to secure a deal with Iran over its nuclear programme as a part of his foreign policy legacy. With sanctions biting and oil prices falling, Iran’s economic woes worsen by the day, giving the president apparent leverage to secure a deal.
But the mood in Congress has always been distrustful of Iran, and it will be even more so in January when Republicans are in the majority in the Senate.
Hints of an alliance with Iran would further inflame congressional opinions, which could be a deal-breaker for any agreement with Tehran. Only Congress has the power to lift sanctions, so the Tehran regime may have legitimate doubts that a weak president can lift sanctions as part of a nuclear deal.
Tehran would be right to doubt. Congress has been in no hurry to lift sanctions on Cuba, even though their effect since 1959 has been to keep the Castro brothers in power. There are no votes in lifting sanctions on old bogeymen.
The White House has also to navigate the suspicions of its Arab allies, notably Saudi Arabia.
In Iraq, policy is pulled in different directions by goals that are incompatible in the short term: destroying the terrorist threat of ISIL and reviving Iraq as a single state which has the loyalty of all its Shia, Sunni and Kurdish citizens. To achieve the first goal quickly requires coordination with Iran and its “foreign legions” but unleashing these sectarian forces will kill the prospects for a unified Iraqi state.
Finally, in Syria, the US has to grapple with the contradictions of bombing ISIL forces without giving the regime of Bashar Al Assad a free hand to crush the beleaguered “moderate” opposition that Washington keeps promising, with some lack of conviction, to train up to march on Damascus.
This is a true policy swamp. Mr Obama recognises this and would have preferred not to wade into it. The same seems to be true of Michele Flournoy, a Democratic high-flyer who was a leading candidate to be the new defence secretary but who has asked to be dropped from consideration.
Carl von Clausewitz, the Prussian general who is seen as the father of modern strategy, wrote that war is the continuation of policy by other means. In this case, the policies are so unclear that it is hard to see how warfare can enhance them or what victory would mean.
Perhaps we should look on the US intervention not as a war but as an exercise in holding the ring so that none of the contesting powers – ISIL, the Assad regime or Iran and its proxies – gain the upper hand. In other words, a policy of triple containment.
By this measure, Washington has made some modest gains. ISIL’s advance has been halted and Baghdad has struck a deal with the Kurdish region on oil revenues, lessening the risk of Iraq breaking into regions. But for the air campaign against ISIL and the high costs – in money and civilian deaths – this might not be a real war but a phantom one.
Alan Philps is a commentator on global affairs
On Twitter: @aphilps