By Mark Valencia, Special to CNN

Editor’s note: Mark Valencia is a Hawaii-based maritime analyst and political commentator and author of ‘The Proliferation Security Initiative: Making waves in Asia.’ The views expressed are his own.

Enough already! Nasty rhetoric is one thing. But confrontation between warships, including the locking on of fire control radar, is downright dangerous. The implications of an outbreak of military hostilities between China and Japan are too horrific to contemplate, and clearly this level of tension and instability is unacceptable – not only for the parties directly concerned, but for their neighbors and extra-regional partners.

What is needed are some guidelines or an agreed declaration of expected behavior in disputed areas that could avert such confrontations. More specifically, China and Japan need to forge at least a rudimentary “incidents at sea agreement” – and fast!

So what is an incidents at sea agreement (INCSEA) and why would it work? In the late 1960s, there were several incidents between the U.S. and Soviet navies, including planes of the two nations passing particularly close to one another or ships and aircraft making threatening movements – very similar to what has been happening in the East China Sea between China and Japan.

But in March 1968, the United States proposed talks on how to prevent such incidents from becoming more serious or even leading to an outright military clash. According to the State Department, the military-to-military agreement provided for:

- Steps to avoid ship collisions

- Non-interference in the “formations” of the other party;

- Avoiding maneuvers in areas of heavy sea traffic;

- Requiring surveillance ships to maintain a safe distance from the object of investigation so as to avoid “embarrassing or endangering the ships under surveillance”;

- Using accepted international signals when ships maneuver near one another;

- Not simulating attacks at, launching objects toward, or illuminating the bridges of the other party’s ships;

–Informing vessels when submarines are exercising near them; and

- Requiring aircraft commanders to use the greatest caution and prudence in approaching aircraft and ships of the other party and refraining from simulated attacks against aircraft or ships, performing aerobatics over ships, or dropping hazardous objects near them.

The agreement appears to have helped the two sides’ militaries avoid clashes. In subsequent years, such agreements were reached between Russia and South Korea and Russia and Japan, and there is a maritime consultative agreement between the United States and China that they have now agreed to reactivate.

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Recent developments have made it clear that an INCSEA is needed now between China and Japan.

For many years, the East China Sea was a dangerous “no man’s land.” But as I have noted before, China and Japan avoided escalating tension by refraining from extending their maritime jurisdiction and in general foregoing provocative activities. Once they extended their jurisdiction and disputes arose, they forged an ad hoc maritime conflict avoidance regime that incorporated principles of self-restraint and the sharing of resources in disputed areas. This included an agreement to share fish stocks in defined portions of their disputed area. They also agreed in principle to implement joint development of seabed resources in the central East China Sea. In addition, as I wrote in the Japan Times, after several serious incidents, they established a mutual “prior notification” regime for scientific research in their disputed area in the East China.

But this is all unraveling because of the recent resurgence of sovereignty and jurisdictional disputes.

If the two cannot quickly negotiate a military-to-military INCSEA agreement, then perhaps an agreed declaration of expected behavior would be a logical next step. But what should such a declaration cover and contain? Obviously there is a need for a clause addressing the question of arrest and detention of fishing vessels and crew of fellow claimants. It should also govern any and all other activities in disputed areas, for example, resource exploration and exploitation, marine scientific research, marine and aerial “spy probes,” and other military activities in disputed EEZs.

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First and foremost, there must be a clause that states that nothing in the declaration prejudices any party’s sovereign rights or jurisdiction in the territory they claim, territorial sea, continental shelf, EEZ or their rights and responsibilities under the 1982 United Nations Convention on the Law of the Sea. It should reaffirm the use of the sea only for peaceful purposes and the resolution of disputes without the threat or use of force in accordance with international law. It should also reaffirm the freedom of navigation and overflight in accordance with international law. The parties would commit to exercise self-restraint in the conduct of activities that might complicate or escalate disputes, including refraining from occupying presently uninhabited features.

They would also agree to negotiate provisional arrangements of a practical nature to manage and share the resources and activities in disputed areas. And they would agree to notify each other of any pending activities including military exercises in waters of interest to other parties. Outside parties would also be encouraged to adhere to the provisions of the declaration. Looking forward, the parties would agree to consider making the declaration a formal Code of Conduct.

This all may seem to be wishful thinking. Yet a similar declaration was forged in 2002 by the Association of Southeast Asian Nations and agreed to by China for the South China Sea, after years of confrontation and actual conflict over similar maritime disputes.

China and Japan need to negotiate either an INCSEA or a declaration of conduct now – and implement it before this situation really gets out of hand.