four thousand american troops in west africa are intended to prevent further outbreak in america...,

WaPo |  By early September, there was still no agreement among the major global health organizations and governments on how to respond to the epidemic. Unlike other disaster responses, such as the one after the earthquake in Haiti in 2010, no major U.N. operation was in place. And despite a 20-page "road map" that the WHO had introduced, it was unclear how anyone would put it into effect.

"Six months into the worst Ebola epidemic in history, the world is losing the battle to contain it," Liu, of Doctors Without Borders, told the United Nations on Sept. 2. For the first time, she implored countries to deploy their military assets - something her organization had previously opposed for health emergencies.

World Bank President Jim Yong Kim was beyond frustrated. Kim, a doctor and an expert on infectious diseases, called an emergency meeting for Sept. 3 that would include major decision-makers from the government and the private sector.

About 50 people crowded into the 12th-floor conference room at the World Bank's Washington headquarters. Gayle Smith from Obama's National Security Council was on the telephone. A senior WHO official participated by video link. The session lasted two hours.

Frieden showed up and had a dire warning: The response was like "using a pea shooter against a raging elephant."

Kim warned, "The future of the continent is on the line."

By the first week of September, senior officials across the U.S. government had come to a grim realization: The civilian response was never going to happen fast enough to catch up with the epidemic. The CDC had managed to put more than 100 staff members on the ground and the U.S. disaster relief team had dispatched 30 more, but they and other aid workers were facing too big of a challenge. Only the U.S. military had the capacity to move with enough speed and scale.

The White House was talking to the Pentagon about deploying a field hospital to treat any health-care workers who might get sick, an effort to reassure potential volunteers. U.S. military planners in West Africa were telling Washington that 500 treatment beds were needed for sick patients. A host of agencies across the government had to work out complicated logistics.

On Sept. 7, Obama said on NBC's "Meet the Press" that he intended to use the U.S. military to provide equipment, logistical support and other aid to West Africa.

But the region now had thousands of confirmed Ebola cases, and there was nowhere to treat the sick and the dying. On Sept. 9, Sirleaf sent Obama an urgent plea:

"I am being honest with you when I say that at this rate, we will never break the transmission chain and the virus will overwhelm us," she wrote.

The next day, high-level administration officials met at the White House to discuss military options. "People were asked to do more homework on the how," and then report back two days later, on Sept. 12, a senior official said.