A V-22 Osprey landing on a flight deck, possibly of a carrier or amphibious assault ship. In the top left is a departing Sea King helicopter, the aging craft which the new tilt-rotor will be replacing.

Japan wants no part of America's wonder plane, the V-22 Osprey.

An aircraft that can transform between a long-distance turboprop transport and a medium lift helicopter -- known as a tilt rotor -- the Osprey has long been pinpointed by the U.S. military as a major 21st century replacement for its aging fleet of decades old helicopters.

Opinion of U.S. troops rose in Japan last year after the Fukushima disaster. The dedication and professionalism of U.S. forces providing disaster assistance made a deep impression on the Japanese public, especially when compared to the lackluster performance of their own government.

But the Monday arrival of a dozen V-22s at a U.S. airbase in Iwakuni, on the western tip of Japan's main island of Honshu, sparked widespread opposition and anger, both from the public and the Japanese defense ministry. Activists gathered in about a dozen small boats to protest the temporary stationing of the aircraft in Iwakuni.

Although the Ospreys have already been unloaded from ships and assembled, their final destination is expected to be the ever-controversial Futenma Marine air base in southern Okinawa. Demonstrations from group opposing the U.S. presense and the Osprey took place outside Futenma on Monday.

A history of aircraft crashes, long resistance to U.S. basing and military friction with civilians, and staunch opposition from local governments, particularly focused on Okinawa, has created major disagreements between Tokyo and Washington over the status of U.S. forces deployed to Japan.

Futenma air base is located in a densely populated urban zone. In 2004, a CH-53 Sea Stallion (a heavy helicopter) crash-landed into an Okinawa International University building nearby, luckily resulting in no deaths. A string of accidents to the V-22, which entered service in 2007, has raised fears that similar incidents could occur again.

Last Friday, Japan's Vice Defense Minister Shu Watanabe told reporters that If the U.S. forces the issue, it could become a long-term problem affecting the good relations between us.

Earlier In July, U.S. Secretary of State Hillary Clinton told the Japanese press that We will work closely with our Japanese partners to ensure that any American military equipment brought into Japan will meet the highest safety standards.

The U.S. has maintained that switching to the Osprey will improve the safety and performance of its aircraft. After all, the CH-46 Sea King helicopters it is replacing are from the 1960s.The current group of 12 Ospreys are meant to partially replace 24 aging Sea Kings slated for decommissioning.

Local Okinawan politicians point at Osprey crashes in April in Morocco (injuring five) and in June in Florida (killing two) as examples of the plane's continued troubles.

The U.S. military says that the Osprey has already logged 150,000 flight hours. For every 100,000 flight hours, there are fewer than 2 accidents, far below the average of almost 2.5 for other Marines aircraft.

'Vital' To The Asia-Pacific?

The U.S. Embassy in Japan released a press statement on Monday calling the V-22's arrival in Futenma a necessary and vital component in fulfilling the United States' commitment to provide for the defense of Japan and to help maintain peace and security in the Asia-Pacific region.

That hasn't assuaged the Japanese public's concerns about the plane, or the nature of living so close to U.S. bases on cramped Okinawa.

In the 1995, the rape of a 12 year-old Okinawan girl by three U.S. service members outside Futenma sparked widespread anger and resentment. A year later, Japan and the U.S. agreed that the airbase would be closed down and moved to Henoko Bay, further north on the island.

However, concerns about the economic costs and damages to pristine local environment have delayed the actual relocation. Many Okinawans, fed up with the U.S. forces, which they blame for higher crime and greater safety risks, instead think they should be sent overseas or to another area of the country entirely.

As of late March 2011, 19,000 of America's 34,221 total active duty troops in Japan were Marines located on various bases on Okinawa. Both governments have agreed to moving 9,000 of those soldiers to other locations (5,000 to Guam and 4,000 to other bases in the Pacific), but no firm date has yet to be set. The cost of moving them and building new bases elsewhere will be some $8.6 billion, $3.1 billion of which will be paid by the Japanese government.

Okinawa, independent from Japan until 1871 as the Ryukyu kingdom, historically had a distinct culture and language. In the years after World War Two, local populations have grown to resent the pressure and burden placed on them from Tokyo's acquiescence to the island becoming the major staging area for U.S. forces in the country.

As for the Osprey itself, the new plane has the potential to improve the training and capabilities of U.S. troops in Japan. First flown in 1989, co-developed and built by Bell and Boeing, the Osprey suffered from years of test troubles and rising costs, not unlike many other aircraft bought by the Pentagon. Since initial test flights, the plane has suffered 7 crashes, resulting in 36 deaths. The Pentagon is adamant in arguing that the plane's safety standards have improved dramatically with design changes and additional adjustments, as shown through its excellent performance in Iraq and Afghanistan in past years. The craft does have an impressive range of 2,300 miles and moves at speeds around 300 miles and hour, outperforming normal helicopters and allowing U.S. forces to travel further along the Japanese coastline and the Western Pacific's long maritime distances.

The V-22 has cost approximately $27 billion to develop, and procurement costs will likely amount to another $27 billion. 160 have been built so far, but the Marines themselves are expected to need some 360. But even if the craft is gaining infamy in Japan, there are reports that it has already overcome its poor starting reputation, receiving interest from the militaries of Israel, the United Arab Emirates, and Canada. 

The Okinawan island chain's strategic location, flanking China's coastline to the East, along with its vicinity to larger Japanese islands and the Korean Peninsula, makes it a pivotal strategic location in the Western Pacific for U.S. forces. That means the total removal of U.S. forces from the area is a near impossibility, even if absolute numbers are set to decrease.

The recent incident is revealing major differences in the U.S.-Japan defense pact, even as the two look to work together to deal with China's rising military power. Japan after al, maintains that the Senkaku Islands, which China calls the Diaoyu Islands, are administered as part of the Okinawa government.

Kent Calder, a Japan expert at Johns Hopkins University, told the Wall Street Journal on Monday that the tensions between Japan and the U.S. over the Ospreyjeopardize some of the quiet progress made on other defense issues.

The U.S. Embassy noted that U.S. forces in Japan will refrain from any flight operations in Japan until the results of investigations into recent incidents in Morocco and Florida are presented to the Government of Japan and the safety of MV-22 flight operations is reconfirmed. This information is expected to be presented to the Government of Japan in August, said an Embassy statement, using the Osprey's designation in Marine service.