Since 2006, the Chinese nuclear arsenal has increased by 1/3.

When one considers the strategic needs of China, they would generally be geared towards protecting supply lanes for oil and other strategic materials, but we see a buildup here that is largely ICBMs and nuclear cruise missiles, which are useless in this scenario:

In fact, the only realistic use for these weapons is to deter the US from using their weapons as a threat to forestall specific Chinese actions **cough** Taiwan **cough**.

Were this simply a modernization, I don’t think that you would see an increase in warheads, because the older liquid fueled missiles would be decommissioned, and they have not been.