The "pivot to Asia" is an idea. It's not a doctrine, like the Monroe Doctrine, the Truman Doctrine, the Eisenhower Doctrine, or the Bush Doctrine, all of which were based on the statement, "If you do X, It's War!"(Or, in the case of the immortal Bush doctrine, If you're thinking of doing X, or I think you're thinking of doing X, or if you're not thinking of doing X but I want to bomb you anyway, It's War!)
China faces a dilemma with its growing power. On the one hand, it will be confronted by neighbors like Vietnam, the Philippines and Japan, and other stakeholders like the US if it makes use of its power.
On the other, if China conceals its power, its determination to safeguard territorial integrity will be underestimated, which would further foster the unscrupulousness of countries like Vietnam, the Philippines and Japan.
The South China Sea disputes should be settled in a peaceful manner, but that doesn't mean China can't resort to non-peaceful measures in the face of provocation from Vietnam and the Philippines. Many people believe that a forced war would convince some countries of China's sincerely peaceful intentions, but it is also highly likely that China's strategy would face more uncertainties.