Based in Japan the “G-Dub” is widely believed to carry a typical deployment of 100 nuclear warheads. Japan has revealed recently that they have always turned a blind eye to this despite official policy prohibiting nuclear weapons on their soil.
Were the Vietnamese upset with this show of force just outside their territorial waters? No, in fact they could not have been more pleased as they chose the location. This is the part of the South China Sea that they claim as their own that includes a number of small islands known as the Spratly and Paracel Islands. These islands are the reason Hanoi and Washington are getting so cozy militarily.
The super carrier task force arrived off Vietnam having just completed joint exercises with South Korea and during the entire trip from Japan they were shadowed by a number Chinese warships. You see Beijing claims absolute sovereignty over the entire South China Sea, its islands, fishing grounds, oil & gas reserves and the sea lanes themselves. They don’t care much for trespassers but so far have been out gunned by the USN.
Vietnam has tried very hard to cultivate relations with the US, especially after the collapse of their primary benefactor, the Soviet Union. Before, during and after the US-Vietnam War, the Vietnamese were at war with China and repelled several invasion attempts that killed large numbers on both sides. The third and final invasion took place in 1979 and China withdrew after taking heavy losses but looted and laid waste to the northern part of Vietnam on the way out.
China has made no secret of the fact that at some point they intend to throw the US out of its South China Sea. To press home that point they have recently announced the pending deployment of a new generation of hyper-sonic anti-ship missile called the Dong Feng 21D. With a large conventional or nuclear warhead and a 900 mile range they are reportedly capable of defeating any counter measures and intercepting a moving target. Of course at 6000 miles per hour it closes the 900 miles in 9 minutes, so even at flank speed a carrier would only move maybe five miles, not quite like shooting fish in a barrel but close. Some reports are that the new missile may have a much longer range on the order of 2000 miles.
There is a debate about when the weapon will be deployable, it could be ten years or maybe less than two. There is no question that China is capable of producing such a weapon thanks to technology sharing by American companies like Boeing and Lockheed. In order to get access to cheap manufacturing, US companies are required to turn over information that prior to the Bush Administration people went to prison for giving up.