The director general of I.A.T.A., Tony Tyler, has criticized the “gap in the system” that sent Flight 17 on its ill-fated flight path, and has called for an overhaul of how information about missile threats is collected and disseminated. Under the current system, national governments assess threats within their own airspace before making recommendations to domestic civil aviation authorities. International bodies like the European Aviation Safety Agency collate this information and issue advisories to airlines.

It is now clear that such sources cannot always be trusted to make objective judgments. Ukraine is only the most glaring example. Governments will not always deem it in the national interest to release sensitive — read, embarrassing — security assessments. Politicians often balk at measures that tarnish their reputation and reduce the overflight fees paid by airlines.

Perhaps mindful of this, airlines make in-house risk assessments beyond the patchwork of information they are fed by the various national authorities and international bodies. British Airways, for example, chose to reroute flights around eastern Ukraine back in March. Some 75 other carriers, however, were still sending about 400 flights a day into harm’s way until the loss of Flight 17.

To date, nothing has changed. The Iraqi C.A.A. still insists that its airspace is safe from the forces of the Islamic State in Iraq and Syria, despite the fact that ISIS fighters — who have freedom of movement between the two countries — have overrun army positions in eastern Syria. The Syrian government forces, like Ukraine’s rebels, have Buk missile systems supplied by Russia.

Many airlines are therefore avoiding Iraqi airspace. Emirates was the first to do so, in July, even as Etihad, another United Arab Emirates carrier, maintained that Iraqi skies were safe. (In August, Etihad suspended routes over northern Iraq, but insisted that there was no evidence that jihadis could bring down aircraft.) Both cannot be right; the lack of unanimity means that passengers are not being equally protected.

The I.C.A.O. and I.A.T.A. are rightly evaluating whether to create a new, global body that collates and distributes region-specific risk assessments to airlines. They recognize that a single, neutral source of information would be preferable to the existing mishmash of advisories. But they have no mandate to empower such a body, and governments that would seek to play down internal threats would not willingly disclose intelligence to third parties.

The onus of responsibility rests with democratically accountable states that have resources spread across the globe and command more responsive spy agencies. It is not a promising start that the United States has already distanced itself from the United Nations task force initiative. But if we do not want the risk of future Flight 17s, international travelers must not accept the flawed system.

Martin Rivers is an aviation journalist.