On one hand, global and regional powers are at pains to show off their military capabilities in conducting the search.

A British government statement on its submarine deployment earlier this month captures the mood: “While we do not routinely comment on submarine operations, we can, exceptionally, confirm that HMS Tireless has been tasked to assist in the humanitarian search mission for Flight MH370.”

On the other hand, the fear of conflict in Asia has made countries wary of exposing too many of their abilities in sensitive areas such as satellite imaging, surveillance technology and underwater listening.

The search for the Malaysia Airlines flight carrying 239 people has entered a "critical juncture", Malaysia's acting transport minister Hishammuddin Hussein said on Friday, suggesting the lack of any findings will push authorities to discuss the "next move".

An ex-RAAF officer now active in the aerospace industry described the search, which has been going for six weeks, as a “really interesting dance” in which civilian and international militaries “want to co-operate without disclosing or compromising their capabilities”.

Global powers would also be tempted to keep an eye on each others’ capabilities, the expert said.

Military and commercial imaging satellites have predictable, low-earth orbits. If photos released of a certain spot in the ocean are thought to have originated with classified satellites, competing powers could triangulate which satellite is the source, potentially learning about its capabilities, he said. .

“Boiled down, it becomes a matter of maths.”

And while governments peer at each others’ satellite abilities, it is expected that any image that is too revealing of a nation’s capability would be “fuzzed-up” before public release.

Driving these concerns are the vastly different strategic objectives of the countries involved, which loom behind the humanitarian mission to determine the fate of the the plane.

China, in addition to the concern for its 153 citizens on the flight, wants to demonstrate the growing reach of its navy, its operational expertise, and the ease with which it can deploy far from its shores.

The United States wants to show its continued presence in the region, as part of its pivot to Asia.  It also has an interest in learning what happened to the US-built plane.

Australia can reinforce its image as a vital regional power, able to forge co-operation among Asian neighbours.

"It’s heart-rending to see the families [of the missing passengers] in the middle of high-stakes intelligence games, but they are caught in a global geopolitical game of cat-and-mouse," said US-based Everett Dolman, author of Astropolitik, a study of geopolitics and space.

The geopolitical setting had given the search a unique quality, Dr Dolman said. Military transparency, he said, was typically considered a confidence-building measure in much of the West. In ‘‘much of Asia — and in every intelligence agency in the world’’ the opposite view was held, he said.

“If your opponents know precisely what your capabilities are, they can come up with a plan to defeat you in detail."

Behind it all are the concerns of a potential Asian conflict involving China, Japan and others. In this competitive sphere, countries are also pushing their technology to new levels to find the missing plane.

The Bluefin-21, the undersea drone contracted by the US Navy, has dived "beyond its depth rating" of 4500 metres in an attempt to locate the plane's black boxes.

Earlier, Royal Australian Navy Commodore Peter Leavy detailed modifications made to RAAF’s P-3 acoustic processor used for underwater listening. The changes were "only started after the MH370 aircraft was lost", he said.

British satellite firm Inmarsat, which operates 11 satellites in geostationary orbit, pulled a week of all-nighters for “an analysis that had never been done before” that narrowed down a more precise point of where MH370 dropped off the satellite communication grid. That helped lead to the current search zone, where the underwater pinging has been detected.

These are the modifications and innovations linked to the search for MH370 that the public knows about. With so much national pride at stake at a time when a peace in Asia is less certain, behind-the-scenes competition is likely.

“There is no doubt that some of the technological advancements have been made for the search,” said IHS Jane’s Asia Pacific defence industry analyst Jon Grevatt. “Some have never been used before.”

“This search is pushing technological boundaries and it will lead to advances in companies that make the equipment,” he said.

Whether the militaries' redoubled efforts in the time of crisis will help build confidence or instead fuel competition won’t be known for some time yet. Until then, the search continues and the families’ wait goes on.