The Obama administration last week gave diplomatic status to a coalition of moderate opponents of the Syrian government. President Barack Obama and Secretary of State John Kerry even entertained the coalition's president, Ahmad Jarba, at the White House. But the president showed no sign of granting Mr. Jarba's request for weapons to counteract Syria's use of helicopters to deliver masses of lethal "barrel bombs" against civilians in rebel-held areas.

So, in effect, the administration's do-nothing policy on Syria remains unchanged since President Obama caved on his "red line" pledge to take firm action against the Assad regime if it used chemical weapons.

The three-year Syrian civil war has already led to nearly 3 million refugees and in all probability well over 100,000 deaths. It has also provided a foothold for radical Islamist groups affiliated with al-Qaida.

There are legitimate fears that if the United States arms the moderate rebel forces with anti-aircraft weapons they might fall into the wrong hands. But a failure to arm the rebels virtually guarantees that Syrian President Bashar al-Assad will continue his scorched-earth attacks, which have already succeeded in weakening the opposition, while killing thousands of innocent civilians.

Meanwhile, leading Iranian politicians told the Guardian newspaper last week that Iran has won the war in Syria to keep President Assad in power and, "The Americans have lost it."

As Mr. Jarba pointed out in a talk at the U.S. Institute for Peace last week, to restore a balance of power and prepare an opportunity for a negotiated settlement of the civil war in which Mr. Assad steps down, it will be necessary to neutralize Syria's air force.

At his meeting with Mr. Jarba last Thursday, Secretary of State John Kerry said the Syrian opposition leader "understands better than anybody, the stakes and the struggle and the fight against extremism." Mr. Kerry added that the United States remains "committed to do our part to support the moderate opposition in its efforts to provide a legitimate voice to the aspirations and hopes of the Syrian people."

But a State Department spokeswoman later told reporters, "I have nothing to announce in terms of any change in our position," which limits U.S. aid to the rebels to non-lethal assistance.

Critics of the arm's length policy followed by the Obama administration say it has given radical groups an opening to establish themselves in Syria and Iraq. Even Secretary Kerry reportedly told Mr. Jarba last week that the administration "wasted a year" by failing to help the rebel movement.

President Obama has at times posed the Syrian question as one of whether to intervene directly or stay on the sidelines. On his recent Asian trip he said his critics want him to jump "headlong into a bunch of military adventures that the American people had no interest in participating in and would not advance our core security interests."

But as U.S. Ambassador to the United Nations Samantha Power recently observed, all or nothing is a "false choice," because there are many steps short of full military intervention that could be taken to avoid a humanitarian catastrophe like Syria.

Arming the rebels effectively is one such choice. Had that been done in 2012, the civil war might now be over with much less human suffering. And the risk of the anti-Assad forces being taken over by Islamic radical terrorists would have been minimized.

At this sad point, however, the laments over what could have been are not a convincing argument for continued American inaction on Syria.

What is needed now is a belated but effective U.S. effort - including carefully limited arms supplies - to help the moderate opposition forces finally succeed in their struggle to oust Assad.

Anything less would send another shameful signal of American acquiescence to the ongoing human slaughter in Syria.