YOKOTA AIR BASE, Japan — As the specter of potential nuclear contamination spread throughout Japan in the week following the March 11 earthquake and tsunami, the top U.S. military commander in the country felt as uncertain as many of the Americans under his protection.

It wasn’t until March 18 — a day after the Defense Department announced it would pay for families of servicemembers to leave Japan — that U.S. Forces Japan commander Lt. Gen. Burt Field felt personally sure that radiation emanating from the Fukushima Dai-ichi nuclear plant posed no major threat to the Tokyo area, where tens of thousands of Americans live and work on U.S. military bases.

“We weren’t sure of how much radiation was being released,” said Field, who spoke with Stars and Stripes last week for the first time since the March 11 disaster. “We weren’t sure how long that radiation was going to continue to be released (and) we weren’t sure how far that it would spread.”

In the early days of the disaster, details on the extent of the damage to the multiple reactors at the Fukushima prefecture plant were publicly scarce. Japanese government and Tokyo Power and Electric officials said little, and contamination made data gathering at the plant potentially fatal.

During that time, officials from the U.S. Nuclear Regulatory Commission, Department of Energy and Defense Threat Reduction Agency arrived in Japan to measure the potential danger, Field said.

Sometime between March 14 and March 15, U.S. forces began flying search patterns with Department of Energy systems onboard designed to assess radiation, Field said.

For days afterward, experts modeled the growing radioactive plume blowing away from the plant.

“On the 18th of March, I had a very long discussion with a couple of these experts and … I didn’t think there was going to be any health risk from this reactor in the greater Tokyo area,” Field said. “That was my personal opinion, based on my education of that week.”

But by that time, rumors had already turned concern into full-blown fear for many on U.S. bases in mainland Japan.

People at Yokosuka Naval Base and Naval Air Facility Atsugi, each about 40 miles from Tokyo’s city center, had been advised by local commanders not to go outside on the morning of March 15 because of radiation levels that, while elevated, were not considered dangerous.

By March 17, talk of the radioactive plume blowing south had reached Tokyo-area bases and exacerbated fears.

Field said he understood those fears, but acknowledged that the enormity of the situation took time to fully analyze.

“Unfortunately, it takes a little while to develop that picture, and we weren’t ahead of the rumors that were rampant or the emotions that were being played out,” Field said.

More than 9,500 people would end up voluntarily leaving Japan on Defense Department orders as the crisis lingered, according to military figures.

U.S. Forces Japan is now in the process of studying the lessons it has learned, both in its on-base responses and during its Operation Tomodachi disaster relief operations, which at their peak included more than 24,000 U.S. servicemembers.

Field said it’s too early to say how those lessons will translate to direct action, but he also put out a clear message to his personnel: do a better job of communicating.

“Whatever you know, you need to tell more people more of what you know, and you need to do that more often than you think you need to, especially if you’re leading an organization,” Field said. “Continually inform people you work with what you have found out.”

Despite any shortcomings, Field believes that the relationships in place as a result of the U.S.-Japan alliance, along with Japan’s high-level capabilities, enabled U.S. forces to provide disaster support faster than they could have just about anywhere else.

The military delivered 189 tons of food, 87 tons of supplies and two million gallons of water to the affected areas as of April 8, according to U.S. Forces Japan figures.

“It’s our duty to be part of the solution in times of tragedy, and [Japan] accepted our help,” Field said. “We made sure from the very beginning that they knew we were supporting their efforts.”

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