Why Singapore is an imperfect parallel for Pearl Harbor

Were the Americans at Pearl Harbor blindsided in the same way as the British at Singapore?

Not exactly; Singapore had strong maritime defenses but suffered from weak land command and force allocation, while Pearl Harbor failed to organize defenses around assets already concentrated there.

Pearl Harbor and Singapore did not fall through the same kind of blindness. Singapore had substantial seaward defenses, while its central weakness lay in the land campaign, confused command arrangements, and the failure to conduct an orderly withdrawal to defensible lines. Britain had also been at war for two years, so many of its better formations and officers were committed in North Africa, Europe, Iran, and Iraq. Japan sent experienced forces into Malaya, whereas Pearl Harbor theoretically contained some of the United States' most important fleet and air assets. The comparison separates inadequate defense of a strategic center from a defended naval base undermined by failures elsewhere in a joint campaign.