> This is a dispute in which only the direct stakeholders (countries whose territorial waters adjoin this area) or international institutions such as the United Nations should get involved

I disagree. If you have a military base in or a military or economic cooperation agreement with any of the adjoining nations, or if part of your economy transits the adjoining area, you should feel free to get involved at any time. You take the risk, but really, in a case like this it'd be dumb not to get involved when you are so deeply integrated.