Willow Run 6-3
Given that the aircraft appears to have disappeared in international waters, primary responsibility for the investigation will lie with the Malaysian authorities. If it subsequently comes to light that the aircraft crashed in territory claimed by another sovereign state, then they will assume a lead in the investigation.
It would be futile to attempt to force any nation to reveal details that they are not prepared to divulge voluntarily. Commercial organisations would doubtless be prepared to reveal data and cooperate with investigations so long as their costs were covered. Commercial interests will force companies like Boeing to participate because they are anxious to prove that it is not a fault in their product that was responsible for the event.
So basically it comes down to money. How much will it cost to equip every aircraft with a tamper proof satellite position transponder? Who will be responsible for gathering and safe guarding the data? Who will set the technical specification? How will international agreement be reached? How will compliance be enforced? Who is going to pay for the engineering development, international conferences and behind the scenes diplomacy? How long will it take?
The unique nature of this incident has brought together resources from many nations who would not normally be expected to cooperate. Not all of the resources are being paid for by the Malaysian government, but the SAR experience gained by the parties taking part can make it worthwhile. How much to rent a nuclear sub for a day? Opportunity to check out some of the latest Chinese military equipment, priceless.