BEIJING – The frantic hunt for Malaysia Airlines Flight 370 has been, in one way, a nearly miraculous display of international collaboration: Twenty-six nations, many of them rivals, have opened up their territorial waters and airspace or have contributed sensitive technology and surveillance data to a search that has riveted the world.

That extraordinary cooperation has been instrumental in narrowing the search to a remote swath of the southern Indian Ocean this week. But the effort has also underscored the limits of trust among powers like China, Malaysia, the United States, India and Thailand, all of whom bring their own, often competing, strategic interests to bear.

The instruments of the search – advanced radar and satellite arrays, banks of intelligence analysts, surveillance planes and ships – are also the tools of spycraft. And as they have come together, the imperative among participating countries to cloak their technological abilities and weaknesses has proved irresistible, at times hindering the search, military analysts say.

“In Southeast Asia and in the wider region, there is no defense forum that enables the sharing of information and capabilities with regards to something on this scale,” said Jon Grevatt, an Asia-Pacific analyst in Bangkok for IHS Jane’s, a defense industry consultancy. “These countries have tried before to get to a situation in which they are sharing military technologies at a higher level than they are now. They have tried, but it hasn’t really happened. It’s further evidence of the continuing mistrust or lack of confidence in each other.”

For example, Thailand waited 10 days – the most critical stretch of the search – to tell Malaysia that its military radar had picked up the Malaysian flight, a Boeing 777, heading west toward the Strait of Malacca the morning of March 8, when it vanished. A Thai air force spokesman has said officials “did not pay any attention to it.”

Some of the sharpest tensions have risen between China and Malaysia. Chinese officials have denounced Malaysia for its reluctance to share information about the search. Most of the 239 people on the flight were Chinese.

At the same time, China has been unwilling to share with other nations its raw military radar data, even though it might have helped investigators pin down whether the plane had flown north, toward Central Asia. Instead, China, like several other countries, simply told Malaysian officials that its radars had not spotted the plane.

“They won’t share radar data,” said one Western official here who spoke on the condition of anonymity because of the delicate diplomatic issues. “They’ve told us and everybody else, ‘We didn’t see it, period.’ They’re not willing to share the data.”

One possible explanation is that China wants to hide not only its technological abilities, but also the limits of that technology, even as it has grown bolder in asserting itself as a military power, analysts say.

Satellite imagery has been among the most guarded and contested information.

A former senior U.S. military officer said that images of suspected jetliner debris that were released by the Chinese government early on – and later determined to be unrelated flotsam east of Malaysia – had been “dumbed down” to obscure the satellites’ true abilities.

At times, the search has also brought territorial concerns to the fore.

Indian military officials denied a request by China to allow four warships to enter an Indian maritime zone in the Bay of Bengal to help search for the plane, according to a report by the Press Trust of India, the largest Indian news agency. The report said that officials had raised objections on the grounds that Indian military assets in the area were “mainly to guard against China, and these could get exposed if the Chinese warships are allowed in.”

Meanwhile, the most tantalizing clues yet, 122 objects spotted by satellite floating in the turbulent Indian Ocean where officials believe the missing Malaysian jetliner went down, ignited some tantalizing hope on Wednesday. But bad weather, the passage of time and the sheer remoteness of their location kept answers out of the searchers’ grasp.

Nineteen days into the mystery of Flight 370, the discovery of the objects that ranged in size from 3 feet to 75 feet, offered “the most credible lead that we have,” a top Malaysian official said.

With clouds briefly thinning in a stretch of ocean known for dangerous weather, aircraft and ships from six countries combed the waters far southwest of the Australian coast. Crews saw only three objects, one of them blue and two others that appeared to be rope.

But search planes could not relocate them or find the 122 pieces seen by a French satellite. Limited by fuel and distance, they turned back.

– The Associated Press contributed to this report.