Taking a break from his vacation to address the crisis in Egypt, President Barack Obama took a symbolic step toward distancing his administration from the junta ruling Egypt. Yet, by declining to cut off financial aid to the generals, Obama has tied the U.S. to the officials responsible for the deaths of more than 500 protesters yesterday.

Responding to the third mass killing of demonstrators in six weeks by officials in Egypt, Obama announced that he was cancelling Operation Bright Star, a military exercise sponsored by Egypt and the U.S. and scheduled for September. In fact, Obama had no choice. The optics of U.S. forces participating in maneuvers with Egypt's military would have been unacceptable in the wake of the protesters' killings by Egyptian security forces.

The Egyptian brass won't like the cancellation. Bright Star, a massive, multinational exercise that generally takes place every two years underscores Egypt's sense of its centrality to the Middle East.

That doesn't mean, however, that cancelling the maneuvers will encourage the Egyptian military to respect democratic principles. Bright Star also was called off in 2011 amid unrest in Egypt. Egyptian officers have had time to grow accustomed to missing out on it.

Obama seems to hope that continuing to supply $1.5 billion in annual aid will somehow promote good things in Egypt. The evidence, however, doesn't support him. Of that assistance, $1.3 billion goes to Egypt's military, which has unseated the country's first freely elected president and detained him in a secret location. With increasing aggression, it has attacked peaceful demonstrators. And it has declared a state of emergency.

To keep the aid flowing, the Obama administration has blatantly defied a U.S. law requiring a cutoff of assistance to any country in which a legitimately elected leader is overthrown in a coup. The administration's nonsensical approach had Secretary of State John Kerry sputtering that the ambition of the coup leaders was to "restore" democracy. If anyone ever thought that, they can't think it now.

Whether and how the U.S. might have leverage over the generals is no longer the issue. Clearly, $1.3 billion isn't buying the U.S. any influence worth having. It is supporting a murderous regime. The money has to stop.

(Lisa Beyer is a Bloomberg View editorial board member. Follow her on Twitter.)