Japan's dilemma

Just a thought as I was walking home just now. Japan wants the US here, to maintain the region's balance of power. But the US is cautious about being overstretched, and thus wants Japan to play a bigger role in the US-Japan alliance. To keep the US committed to the region, Japan needs to take up a bigger role, answering the US call. But at the same time, if Japan takes up a bigger role, the US no longer needs to maintain a big presence in the region, giving the US a reason to scale down her presence here. Japan is thus faced with a dilemma. If she wants the US to remain in the region, she needs to answer the US call and play a bigger role. Yet if she plays a bigger role, the US can then scale down their presence in the region. It is really being caught in between a rock and a hard place.