Abe’s words at Pearl Harbour were purely for effect, with an eye on China
Jean-Pierre Lehmann says Japanese crimes against humanity extend well beyond the attack on the US base in Hawaii, and Abe’s visit was nothing more than an attempt to cosy up to Washington

In the course of the Pacific War, Japan committed numerous crimes against humanity. The 1941 attack on Pearl Harbour was not one of them.
The attack on Pearl Harbour was an act of war. War material was destroyed, ships were sunk, aircraft were grounded, American soldiers and sailors were killed, an estimated 2,400, along with nearly 70 civilians.
Thus, in the annals of warfare and all its extreme manifestations in the 20th century, Pearl Harbour as such was no big humanitarian deal.
Watch: Shinzo Abe offers everlasting condolences to Pearl Harbour victims
One major criticism was that the Japanese government violated the established protocol of warfare, in that the declaration of war was supposed to precede the military attack, not the other way around.