First come, first served. (English proverb). Those that lie down with dogs, get up with fleas. (Native American proverb, Blackfoot). People are enemies of that which they don't know..
There is another similarity with these two warsâfanaticism and suicide tactics. While Japan apparently did not use suicide tactics at Pearl Harbor, we know of their use of the Kamikaze later in the war. One historian stated that by the end of WWII: 7,465 Kamikazes flew to their deaths; 120 US ships were sunk, with many more damaged 3,048 allied sailors were killed and anther 6,025 wounded Although there may be some question about the exact numbers, the damage done by Kamikazes is almost unbelievable.
The U-boats' main weapon was the torpedo, though mines and deck guns (while surfaced) were also used. By the end of the war, almost 3,000 Allied ships (175 warships; 2,825 merchant ships) were sunk by U-boat torpedoes. Early German World War II torpedoes were straight runners, as opposed to the homing and pattern-running torpedoes that were fielded later in the war.