Job for the ITU
The ITU is probably the only world organisation which should have legitimate authority over which TLD names should be allocated to which nations. I can see justification for some international recognised organisations e.g. .olympics or .fifa for sporting organisations to have TLDs, again such decisions should come under the auspices of an organisation with a UN mandate and not that of a private company. I Don't think such global naming rights should extend to private corporations.
That doesn't make the ITU competent to handle DNSSEC root zone signing or similar technical issues, so a treaty giving the ITU authority over the namespace allocations should require delegation of technical implementation responsibility of these naming decisions to a competent technical company or collection of such to enforce fair competition.