This is the reason of anti-China protests in Vietnam:
China betrays world's trust
VietNamNet Bridge – China's recent illegal acts in the East Sea have seriously infringed on Viet Nam's sovereignty, running counter to international law and practices and damaging the trust held by the world community.
The act of towing a massive oil rig, escorted by a fleet of military, police and fishing vessels, to Lot 143, an oil and gas field inside Viet Nam's territorial waters, last weekend was a brazen violation of Viet Nam's sovereign rights over its exclusive economic zone and continental shelf.
To make things worse, the Chinese ships used water cannons against Vietnamese coast-guard vessels and rammed into them, causing damage to them and injuring crew members.
Turning a deaf year to the resultant outcry across Viet Nam and the world, including from many people within China, a Chinese official brazenly described the rig as a Chinese "border" within the "mobile national territory" of China.
This is against the Declaration of the Conduct of Parties in the East Sea and the spirit of the 1982 United Nations Convention on the Law of the Sea to which China itself is a member.
Numerous countries from around the world, including Japan, Singapore and the United States, have voiced their concern over the escalation, describing the move as a provocation and a threat to regional stability.
The East Sea dispute has also become a hot topic around the world. It has made headlines in the United States and in major German newspapers Die Welt , Die Zeit and Der Spiegel.
"Regardless how much energy actually lies under the ocean, Beijing's heavy-handed approach to regional relations and the damage it has caused could hardly be worth tapping some extra barrels of oil for," commented Holly Morrow, an expert on the East Sea from Harvard University's Belfer Centre.
China's action not only adversely affects bilateral relations, but is viewed as a confidence trick throughout the whole of ASEAN. It challenges the group's Six-point Principle on the East Sea issue adopted in July 2012.
Does such behaviour create among ASEAN members an image of a trustworthy nation? No, it poses a threat to the ongoing negotiations for a Code of Conduct of the Parties in the East Sea (COC), which other nations are working to finalise.
China's act raises the question of whether it is attempting to materialise its self-imposed and irrational "nine-dot" territorial claim in the waters surrounding it.
Why does China keep taking action detrimental to peace and stability in the East Sea? The question needs to be answered because this is not the first time that China has committed acts that further complicate disputes in the area.
It is also not the first time our neighbour has approached the issue aggressively. It can be stated that such thoughts and actions are against the current mainstream goals in the world for co-operation, mutual respect and mutual trust building, which allow disputes to be settled peacefully.
Viet Nam has legal and historical proof of its sovereignty over the Hoang Sa (Paracel) and Truong Sa (Spratly) archipelagos as well as proof of its sovereign right and jurisdiction over its exclusive economic zones and continental shelf under provisions of the 1982 United Nations Convention on the Law of the Sea.
In August 2009, Viet Nam submitted documents to the United Nations Commission on the Limits of the Continental Shelf, with historical legal grounds establishing its sovereignty over the Hoang Sa archipelago.
China's declaration that it holds sovereignty over the archipelago, which it occupied by force in 1974, is groundless.
Viet Nam is doing its best to peacefully settle all disputes with China, even though the situation has grown extremely tense. On October 11, 2011, China agreed to "persistently use amiable consultation to satisfactorily settle sea-related issues to turn the East Sea into a sea of peace, friendship and cooperation". It did this when signing the Six-Point Principle on the Settlement of the East Sea Issue.
The acts taken by China in recent days have clearly had a negative effect on the political trust between the two countries and hurt Vietnamese people. Viet Nam is a peace-loving nation, but it has never knelt down before any hegemonic forces.
Viet Nam will take all necessary and proper measures to defend its legitimate rights and benefits and safeguard its sovereignty.
For the Vietnamese nation, national sovereignty is supreme. No one has the right to violate Viet Nam's independence, sovereignty and territorial integrity.