But apologizing for past failures and repeating the same "never again" mantra is not enough, they need to take action.
In two months, world leaders have a chance to ensure that the responsibility to protect is put at the center of the UN's mission at the UN global summit. But unless the language in the draft document is strengthened it will fail to do so.
In its current form, the agreement will simply provide member states with yet more room to wriggle out of their responsibilities when it doesn't suit their short-term interests.
Protecting civilians has been paid mere lip service for too long. In September, all governments have an opportunity to agree to a new and unequivocal standard for the future. In Bosnia and on countless other occasions the world has learned that compromising on the most basic of responsibilities comes at a high price.