U.S. States without the i's.

[Anomalocaris]

I would think the defeat by Japanese in the Malayan/Indian Ocean campaign to be easily the worst military diseaster ever suffered by Britain. Over 140,000 troops killed or captured, main base in the largest ocean of the world surrendered, newest battleship along with 1 carrier, 1 battlecruiser, several cruisers and many other warships sunk, hundreds of thousands of tons of merchant shipping gone, Royal Navy retreated to Madagascar, Crown jewel colony of India put under dire threat, Britain effectively expelled from the Pacific campaign and permanently discredited as a colonial power in South and Southeast Asia.

In fact I can't think of another case where britian was sent reeling from so large an area that was vital to its interests, nor had britain suffered such losses in the process. Compare to this Market Garden was a pin prick, and defeats in Isandlwana or near New Orlean not even worth mentioning. This is a scale of defeat that precipitates fall of empires. Were it not for the USN distracting the Japanese, there would have been nothing stopping the Japanese from taking control of all of Indian Ocean, severeing all communication with India and Australia, and opening a new land front in the middleeast, cordinating with Rommel, and knock the British out of the war in few more months.