Even then, if we follow the dictionary definition of an arms race as being “competition between countries to achieve superiority in quantity and quality of military arms,” you have to doubt whether this describes what is occurring in Asia. Take the Philippines and Vietnam, which are both investing in their militaries to help protect their interests from China
The writer chose to use a definition from a dictionary, and I can only reason that it was the broadest definition he could find that would suit his purposes. Just because countries are buying arms does not imply arms race.
The parties need to be aware of their mutual antagonism, and their being in a mutually adversarial relationship.
Philippines and Vietnam are both members of ASEAN, and all member countries are in the process of modernizing their military. I would say that South East Asia has never been as stable as it is now.
Try not to buy into the hype.