What are the alternatives? Well, President Barack Obama told the generals off in no uncertain terms after the biggest massacre on August 14. "We appreciate the complexity of the situation," he said sternly. "We recognise that change takes time," he added, his anger mounting. "There are going to be false starts and difficult days," he said, almost in a rage.
The inaction of the US is due to two causes. First, the only major leverage at Barack Obama's disposal, cancelling the annual US$1.3 billion ($1.6 billion) in aid that Washington gives to the Egyptian army, is no threat at all. It would instantly be replaced by the Arab monarchies of the Gulf that heartily approve of the Egyptian Army's coup.
Secondly, Washington remains transfixed by the notion that its alliance with Egypt is important for American security. This hoary myth dates back to the long-gone days when the US depended heavily on importing oil from the Gulf, and almost all of it had to pass through Egypt's Suez Canal. Today less than 10 per cent of the oil burned in America comes from the Middle East, and new domestic production from fracking is shrinking that share even further.
Even if Obama understood that Egypt is not a vital strategic interest and ended US military aid, it would only be a gesture. The International Monetary Fund has already broken off talks on a large new loan to Egypt, and the European Union is talking about cutting aid to the country, but there are no decisive measures available to anybody outside the Arab world, and no willingness to act within it.
There will be no major military intervention in Syria either, although outside countries both within the Arab world and beyond it will continue to drip-feed supplies to their preferred side. And the Iraqi Government's request last Friday for renewed US military aid to stave off renewed civil war has no hope of success. Getting involved again militarily in Iraq would be political suicide for Obama.
So what's left of the Arab spring? On the face of it, not much. Tunisia, where the first democratic revolution started three years ago, still totters forward, and there is more democracy in Morocco than there used to be, but that's about it. The non-violent democratic revolutions that worked so well in many parts of the world are not doing very well in the Arab world.
One reason stands out above all the others. In the Arab world two rival solutions to the existing autocracy, poverty and oppression compete for popular support: democracy and Islamism. The result is that the autocrats exploit that division to retain or regain power. Democracy may win in the end, but it is going to be a very long struggle.
Gwynne Dyer is an independent journalist whose articles are published in 45 countries.