Like the US Army (which utilized French and British tanks in World War I), the Imperial Japanese Army (IJA) did not have tanks of its own in World War I, so it started out by purchasing foreign tanks for evaluation during World War I and right after the war ended. Like many other nations, the Japanese initially didn't embrace the tank, as it didn't have the cavalry tradition. Cavalry was used for reconnaissance in the mountainous countryside, and initially, as with most other armies, the first designs were constrained by the tank's infantry-support role. Building tanks of their own met several problems, as Japan's priority tended to be with naval procurements so production for tank steel was on a lower level. However, they finally began designing tanks by the mid-1920s. Inspired by European designs, the Japanese tank program designed and developed the tanks which facilitated their campaigns in China and the Soviet–Japanese border conflicts, prior to World War II. They introduced many innovations as they built their designs, including bell crank suspensions, as pioneers in amphibious tanks, and the use of diesel engines that were less likely to catch fire compared with gasoline tank engines that were being used at the time. The Japanese generals had made a mistake in their assessment of the tanks used against China, a country whose army had only three tank battalions, and few anti-tank weapons.