While this Japanese task force was operating in the region, a similar Chinese naval task force was operating in the vicinity of Guam. Additionally, the Chinese just launched at least one "anti-carrier" ballistic missile in the South China Sea in the last few days. By 2030 the Chinese may finish their production run of advanced fleet ballistic missile submarines. Although it would only take one of these submarines to completely destroy Japan or multiple major cities in the US, there are military and political leaders in the US who believe they can somehow keep this threat from eventuating by keeping them out of the Pacific and confined inside the island cordon separating the China Seas from the western Pacific.
So the arms race is reaching a point where the advocates of containing China will feel as Germany did in the thirties, "it's now or never." I've heard otherwise credible analysts saying that the economic challenge alone to US dominance justifies this military confrontation in the region.