US Secretary of State John Kerry has called China's move "provocative", while Japanese officials have also criticised it. However, the Association for Southeast Asian Nations - which is closer to the situation and its ramifications - has not blamed China, at least not directly or collectively, despite lobbying by both Vietnam and the Philippines for it to do so.

China's unilateral action has certainly raised tensions and probably violates the spirit if not the letter of the 2002 Asean-China Declaration on the Conduct of Parties in the South China Sea, particularly the provision stating that "the parties concerned undertake to resolve their territorial and jurisdictional disputes by peaceful means, without resorting to the threat or use of force, through friendly consultations and negotiations by sovereign states directly concerned, in accordance with universally recognised principles of international law, including the 1982 UN Convention on the Law of the Sea".

Notably, the declaration says disputes such as those between China and Vietnam, and China and the Philippines, should be resolved between "sovereign states directly concerned". China believes the Philippines has violated this provision and that Vietnam may be on the verge of doing so.

This means there is a fundamental disagreement on the meaning of the declaration's key provisions.

Moreover, the declaration is, after all, a non-binding political stopgap measure to contain a festering dispute, and has been violated by almost all South China Sea claimants at one time or another.

Further, China would probably argue that, in any case, the declaration does not apply to the nearby Paracel Islands.

China has occupied, inhabited and administered the Paracels at least since 1974 when its forces defeated the South Vietnamese forces there. China thus has a claim - based on the UN Law of the Sea - to a 200-nautical-mile exclusive economic zone and continental shelf from the islands. Vietnam disputes Chinese sovereignty over the islands. This means the dispute is probably not the result of a claim by China outside the UN convention, such as its infamous nine-dash line, but a sovereignty claim and boundary dispute solely between China and Vietnam.

This type of disagreement cannot be solved by recourse to the UN dispute settlement mechanism.

It is indeed questionable whether the Paracels can or would generate a full exclusive economic zone and continental shelf. But that has to be determined - not assumed. The Paracels may well have some effect on the placement of a boundary. For what it is worth, the oil rig is situated 17 nautical miles from Triton island in the Paracels and is certainly on China's side of a median line between the Paracels and Vietnam's coast.

Unfortunately, China has chosen not to make clear the basis of its claim. China does not recognise Vietnam's claim to the Paracels. It obviously assumes there is no question regarding its right to drill there and thus has simply proceeded to do so.

According to the UN arbitral tribunal's decision in the Guyana-Suriname case, such unilateral actions would be a breach of the obligations under the Law of the Sea "to make every effort to enter into provisional arrangements of a practical nature" and "not to jeopardise or hamper efforts to reach a final agreement". In the Guyana-Suriname case, the tribunal found that both parties had violated this provision. This may be the case here, too.

Moreover, if ramming by ships is a "use of force", then both parties appear to have violated the UN Charter, the Law of the Sea, the Treaty of Amity and Co-operation in Southeast Asia and the Asean declaration on conduct. The two ideological soulmates need to go back to the negotiating table and work out a provisional arrangement of a practical nature.

By the same token, the May 6 arrest and detention of a Chinese crew and vessel near the disputed Spratly Islands may also be a violation of the Law of the Sea and the Asean declaration.

The point is that all parties in these disputes share some blame. But the US and even Japan have heaped hyperbole and hypocritical criticism on China. US Assistant Secretary of State Daniel Russel has said "we oppose any act of intimidation by vessels particularly in disputed areas". This could apply to both countries, but was clearly aimed at China.

Meanwhile, China views the actions by Vietnam and the Philippines as provocations encouraged by the US. Some may argue - as Beijing does - that these disputes are none of Washington's business.

Others say China's action, coming so soon after President Barack Obama's "reassurance" visit to the region, is a direct challenge to US credibility. This may be reading too much into it. But what makes such criticism particularly annoying to China is that it comes on the heels of a barrage of hypocritical attacks regarding China's declaration of an air defence identification zone in the East China Sea.

To China, this spate of attacks in the Western press seems part of a preconceived plan to demonise it with the intent to isolate it. Hopefully, cooler heads within governments will prevail and this latest clash of wills will be worked out peacefully. But for those who really want an angry and isolated China, and eventually perhaps war - and there are influential warmongers on all sides - this cacophony of China-bashing is certainly setting the stage.