Operation Tomodachi, launched by the United States in response to last March’s quake and tsunami, was an unprecedented effort by Washington and especially the U.S. military to provide relief to disaster victims.

The response generated much good will toward the United States among quake and tsunami survivors in Tohoku and sparked interest among other local governments about how the U.S. military could come to their aid in the event of a similar disaster.

At the same time, U.S. officials and policy experts said Operation Tomodachi was prompted by a unique set of conditions that may be entirely different if a future earthquake and tsunami of similar scale were to strike Japan when the regional security situation is different.

Operation Tomodachi was initiated by the U.S. Department of Defense in joint cooperation with Japanese authorities.

The operation, which started March 12 and lasted until May 4, directly or indirectly involved nearly 24,000 U.S. service members, 189 aircraft and 24 naval ships, at a total cost of nearly $90 million.

The aid efforts focused on the transport of relief supplies, Self-Defense Forces personnel and equipment, and the search of disaster zones for stranded victims. U.S. forces helped rescue about 20,000 people in the first week after the quake, and worked to restore transportation facilities such as Sendai Airport.

“Operation Tomodachi was the first time SDF helicopters used U.S. aircraft carriers to respond to a crisis. The USS Ronald Reagan aircraft carrier provided a platform for air operations as well as a refueling base for SDF and coast guard helicopters,” the Congressional Research Service said in a report released in June.

“The USS Tortuga transported 90 SDF vehicles and nearly 300 SDF soldiers to northern Honshu for relief work,” noted the report, titled “Japan Earthquake 2011: U.S. Department of Defense Response.”

Japanese security experts also gave Operation Tomodachi high marks.

Speaking at a July seminar in Hawaii, Matake Kamiya, a professor of international relations at the National Defense Academy, effusively praised the operation, saying the U.S. military presence increased even as other overseas relief teams were fleeing Japan due to fears over the radiation spewing from the Fukushima No. 1 nuclear plant.

“Operation Tomodachi has proven the Japan-U.S. alliance can function in an emergency in a well-coordinated manner. U.S. military personnel have proven to the fullest degree they are acting for the benefit of the Japanese people,” Kamiya said.

Public opinion surveys showed Operation Tomodachi also gave bilateral relations a major boost.

A June survey by the Washington-based Pew Research Center found that 85 percent of Japanese had a favorable opinion toward the U.S., the highest level in nearly a decade.

The efforts by U.S. Marines to restore operations at Sendai Airport received particularly high publicity. The tsunami flooded the airport and the damage was so extensive the central government initially wrote off the facility.

But the U.S. military, led by about 260 marines, immediately set to work with SDF troops to clean up the debris, and the first relief supplies began landing at the airport just four days after the quake struck. The airport reopened to commercial flights April 13.

U.S. forces also helped clear wrecked ports, including Hachinohe in Aomori Prefecture, Miyako in Iwate Prefecture and Oshima in Miyagi Prefecture.

But Operation Tomodachi also included measures to deal with the unfolding nuclear disaster at the Fukushima No. 1 plant that may have grabbed fewer headlines but proved crucial. Officials from the U.S. Defense and Energy departments, as well from the Nuclear Regulatory Commission, provided on-the-ground expertise, helped monitor food and water for radiation, and provided high-pressure water pumps, fire trucks and protection gear for the efforts to tame the crisis.

In addition, the U.S. Navy provided two barges with 1.9 million liters of fresh water that was used to cool the power station’s three stricken reactors. And the Marine Corps Chemical Biological Incident Response Force provided training to SDF troops operating in the vicinity of the facility.

The U.S. also deployed Global Hawk unmanned aerial drones, which flew over the plant to monitor the reactors and collect data for the Japanese government.

Experts from both countries generally agreed that Operation Tomodachi worked thanks to years of joint training, information sharing and coordination between U.S. and Japanese forces. The training was initiated in 1997, following a security cooperation agreement the previous year that took into account the lessons of the 1995 Great Hanshin Earthquake.

The Kobe quake highlighted fundamental barriers that led to Tokyo turning down, or only accepting under limited conditions, Washington’s offers in 1995 to use U.S. service members, ships and aircraft based in Japan for disaster relief in the city.

But today, Tokyo and Washington are not the only ones reviewing the lessons of Operation Tomodachi. Local governments, especially those in areas seismologists say face the risk of a major quake, are expressing interest in how U.S. forces might play a relief and humanitarian role in the event of a natural disaster striking their municipalities.

“We’re looking at interacting more with regions identified as bad scenarios in a disaster situation and sharing our experience in humanitarian aid and disaster relief,” said Robert Eldridge, deputy assistant chief of staff, government and external affairs for the U.S. Marine Corps in Okinawa.

“Examples include coastal communities such as (those in) Aichi, Mie and Kochi prefectures. Some (municipalities) in Hyogo Prefecture have also expressed an interest in learning more about Operation Tomodachi,” Eldridge said.

Such interest is especially high in Shizuoka Prefecture. Last September, a group of marines visited the prefecture and gave a talk about Operation Tomodachi and the lessons to be learned, while 10 marines also visited the prefecture’s crisis management center in November.

“We’re discussing institutionalization of personnel exchanges, in which marines and civilians visit Shizuoka Prefecture to learn more about their disaster response capabilities and how the prefecture coordinates with the concerned organizations and agencies,” Eldridge said.

“Shizuoka would send officials to Okinawa or other facilities in mainland Japan to learn about the marines’ experience in disaster relief and humanitarian aid.”

Despite the generally positive reviews, a number of experts said a unique combination of factors was responsible for the overall success of Operation Tomodachi, and that this needs to be taken into consideration when discussing the lessons learned.

A November report by the Washington-based Center for Strategic and International Studies and Japan’s leading business lobby, Keidanren, noted Operation Tomodachi went well because it was a peacetime operation carried out in a single country.

“The rapid mobilization of resources for humanitarian assistance and disaster relief, and the relatively smooth command, control and communication arrangements were possible because Operation Tomodachi was a peacetime mission, with the area of operations confined to Japan, and without an enemy seeking to defeat U.S. and Japanese efforts,” the report said.

“It is doubtful this would be possible in a more complex regional contingency,” it concluded.

The biggest area identified for improvement appears to be communications, not just in terms of improving bureaucratic structures on both sides to provide information more rapidly, but also in communications technology itself. This would be especially vital if a future disaster were to occur at a time of war or extreme regional tensions.

“Communications in Operation Tomodachi were largely limited to commercial, unclassified means like unsecure telephones and email, clearly not means that would be effective or reliable in scenarios where an enemy is attempting to intercept communications,” the report said.