Anyone who hoped for a flowering of democracy in Egypt saw those fantasies exploded in a violent government crackdown that killed more than 600 people this week and injured thousands more.

The military that overthrew elected President Mohammed Morsi last month moved brutally this week against encampments of his supporters in the Muslim Brotherhood. That violence quickly spread to other areas of the country and – who would have thought otherwise? – precipitated more protests by Morsi’s supporters. More bloodshed is inevitable.

What was bad becomes steadily worse.

Morsi was democratically elected, Egypt’s first leader so chosen, but he governed as an autocrat, seeking to impose Islamic law and fracturing the country. Against that backdrop, the military last month ousted him – it was a coup, even though the Obama administration shies from using the word – but promised a return to democracy.

That promise was shattered with this week’s bloody effort to crush Morsi’s supporters, however wrongheaded the Brotherhood is about the essence of governing a democracy. Now, the country, the most populous in the Arab world, threatens to spin into chaos.

It was always going to be difficult to graft a democracy onto Egypt, just as it was on Iraq, Afghanistan, Libya and any other country without the history, governmental infrastructure and mindset that democracy needs to take root and thrive. With the military’s brutality, what was difficult has become virtually impossible, at least for the foreseeable future.

In response to Wednesday’s bloodbath, President Obama appropriately canceled a joint military exercise that was to begin with Egypt next month. More problematically, he left in place more than $1 billion in annual aid. It’s a high-wire act – registering Americans’ horror at the crackdown while retaining some ability to influence events there. But without concrete steps by the generals for a prompt return to democracy, the United States has no choice but to end support to the regime.

It is incumbent upon the United States to remain engaged in the Middle East, since it was our invasion of Iraq that changed the dynamic and the balance of power there. However brutal and corrupt Saddam Hussein was, however justified anyone thinks we may have been in invading Iraq, it is plausible to draw a line that extends from that action to the uprisings known as the Arab Spring. We are, if not a participant in these events, then at least an instigator.

Some pro-democracy Egyptians were happy to see the attacks on the Brotherhood; when you have risked your life for democracy, it’s hard to accept less. But what is happening now is liable to drive Egypt further into the abyss. The United States and other nations have little ability to direct events there, but they must do what they can to convince the military to relent. Egypt is too important a player in the Middle East for the United States to merely sit by as it shatters into pieces.