By contrast, the Imperial Japanese Navy had the advantage of a dozen operational battleships early in the war, but chose not to deploy them in any significant engagements. The two Fusō and two Ise-class battleships, despite their extensive modernization and respectable speeds, were relegated to training and home defense, while the two Nagato and two Yamato class were being saved due to fuel limitations for a "decisive battle", which never came. In fact, the only Japanese battleships to see much action in the early stages were the four Kongō-class battlecruisers, which served mostly as carrier escorts due to their high speed and antiaircraft armament.[13]