Recent days have brought two alarming developments in the struggle to contain Ebola. The campaign against the epidemic in West Africa, the only sure way to prevent the spread of the virus to the United States and other countries, fell even further behind. And the discovery that a nurse treating an Ebola patient in Dallas had herself become infected despite wearing protective gear raised questions about the readiness of American hospitals to deal with Ebola patients.

Reassuring statements by health officials that virtually any hospital with an isolation unit could treat such patients now look rashly optimistic. That said, the risk that the Ebola virus might cause outbreaks in this country remains small. By far the greater danger lies in the very real possibility that the virus will continue to spiral out of control in Guinea, Liberia and Sierra Leone and spread from there to other parts of Africa or other continents, opening a wider range of pathways for infected people to reach the United States.

The pace of international aid needs to be stepped up dramatically. This is not a task that can be left to such nongovernmental organizations as Doctors Without Borders, which has heroically provided much, if not most, of the care in the stricken countries. The United States has taken the lead in providing aid to Liberia, a country with long ties to the United States.

The Army has started deploying thousands of troops to the area to help build new treatment centers, perform laboratory tests and train health care workers in how to treat patients, but most of that help has yet to arrive. It was thus disheartening to hear Maj. Gen. Darryl Williams, the commander of the United States Army Africa, dismiss criticism that American aid had been "too little, too late" with the excuse that the Pentagon was simply filling a "small gap" left by other health organizations.

The United States' obligation is greater than that; President Obama needs personally to ramp up the urgency of the American response and the level and speed of the resources provided.

Perhaps the Dallas case will add urgency to those efforts to control the epidemic abroad. The case is not cause for domestic panic, but it is cause for greater vigilance among health care workers.

Even without knowing fully what happened with the nurse, the Centers for Disease Control and Prevention is exploring ways to make it easier to don protective gear, wear it while treating a patient and take it off afterward without infecting oneself.

But all of these efforts, however useful, pale against this country's much larger responsibility to help defeat the disease at its source.