Read the article. I will tell you a political reality: article 9 has kept Japan from being a target. This shift in the status quo has changed that, and now China has been given an excuse. It can now say that Japan is a threat, whereas before, China had no leg to stand on to call Japan a threat. Oh yes, America was a threat, but Japan wasn't. Japan had a "good cop, bad cop" sort of thing going on. Now its just "bad cop, bad cop".
One thing that I hate about this topic is that the stupids on one side are saying Japan needs this change to defend itself, and the stupids on the other side agree. Japan is well armed and long ignored article 9 in order to be so. Japan has been able to defend itself for a long time. This "reinterpretation" (more like a raping of the constitution) was absolutely not necessary in terms of Japan's self defense.
It is my belief that this is simply about money and power, and that is why Japan has at the same time allowed arms sales abroad. Japan is just following America's military industrial complex model, and I wish I could jail all the SOBs behind these moves for life. Crime? Subverting the constitution.
This move was worse than unnecessary. It put Japan back on the map of potential belligerents that someone may decide needs a pre-emptive strike one day.