On three occasions between 1593 and 1637, Japan’s rulers gave serious consideration to sending military expeditions against the Spanish Philippines. Explaining why these plans were not put into effect sheds light on Japan’s military capabilities at the time, especially its lack of naval capacity.
"Wars and Rumours of Wars: Japanese Plans to Invade the Philippines, 1593–1637,"
Naval War College Review: Vol. 69
, Article 10.
Available at: http://digital-commons.usnwc.edu/nwc-review/vol69/iss4/10