1944.

This is coolbert:

During that period of the Second World War [WW2] on several occasions the omnipotence of the Royal Navy [British] in that area of the Indian Ocean challenged by the forces of the Imperial Japanese Navy.

The Japanese Indian Ocean raid of 1942 I had heard of.

The Japanese Indian Ocean raid of 1944 I had not heard of.

Regarding the latter:

"In March 1944, a force of three Imperial Japanese Navy (IJN) heavy cruisers raided Allied shipping in the Indian Ocean. The cruisers departed Japanese-held territory on 1 March with the support of other IJN vessels and aircraft. On 9 March, they encountered and sank the British steamer Behar, with the heavy cruiser Tone picking up over 100 survivors. Fearing detection, the Japanese force subsequently returned to the Netherlands East Indies (NEI), arriving on 16 March. Two days later, most of Behar's crew and passengers were murdered on board Tone."

Prisoners from the sunken Behar executed by beheading much after the fact. Cold and deliberate murder of civilian personnel most cruel and unnecessary.

The English Royal Navy [RN] even up unto 1944 skittish and wary, not willing or able to engage the Japanese fleet in a manner with the necessary aggressiveness and offensive action as required for victory?

That expanse of the Indian Ocean a "backwater" during WW2 but not entirely so!

The capture of Vichy controlled Madagascar in part done to deny the delivery to high-quality graphite as essential to the Nazi atomic bomb project?

Merchant vessels conveying Lend-Lease war-making material to the Soviet also sailing the Indian Ocean, the unimpeded flow of munitions vital to the war effort!

Other than that? Devoted readers to the blog know of more?

coolbert.