Pictured: Imperialists assaulting the North Point in Hong Kong. Click here for more photographs.

Quoting David Swanson’s Leaving World War II Behind, chapter 11:

On the same day of December 7th / 8th — depending on the position of the International Date Line — [Imperial] Japan attacked the U.S. colonies of the Philippines and Guam, plus the U.S. territories of Hawaiʻi, Midway, and Wake, as well as the British colonies of Malaya, Singapore, Hon[g] Kong, and the independent nation of Thailand.

In addition to the Dutch East Indies and the Shanghai International Settlement.

While the attack on Hawaiʻi was a one‐off attack and retreat, in other locations, [Imperial] Japan attacked repeatedly, and in some cases invaded and conquered. Falling under [Axis] control in the coming weeks would be the Philippines, Guam, Wake, Malaya, Singapore, Hong Kong, and the western tip of Alaska. In the Philippines, 16 million U.S. citizens fell under a brutal [Axis] occupation. Before they did, the U.S. occupation interned people of Japanese origin, just as was done in the United States.³¹³

To give an example of how the Empire of Japan seized these properties, here is a quote from Paul H. Kratoska’s The Japanese Occupation of Malaya and Singapore, 1941–45: A Social and Economic History, pages 33–5:

The weakness of British military forces in Malaya and elsewhere in the Far East forced Britain to play for time by offering economic concessions to [Tōkyō] and avoiding open conflict while trying to shore up defences within the region.

[Imperialism] needed to maintain imports of rice, which it obtained from Indochina, British Burma and Thailand, and imports of oil, acquired from Sumatra, and there was pressure to respond to [Imperial] aggression in China by imposing a trade embargo, but action along these lines seemed more likely to spark an open conflict than to cause [Imperial] Japan to abandon warlike activities, and the suggestion was not pursued.

This assessment of the [Axis] response was probably correct, for a Japanese Army–Navy Draft Policy dated 17 April 1941 stated that [Imperial] Japan would attempt to strengthen its defensive position by diplomatic means, but added that if embargoes or other measures threatened the existence of the Japanese empire, military action would be taken.

On 25 July 1941, after [Axis] forces moved into southern Vietnam, the United States froze Japanese funds, and as other countries including the Netherlands followed America’s lead, it became increasingly difficult for [the Eastern Axis] to purchase fuel.

At the end of August the Netherlands Indies banned exports of oil and bauxite to [Imperial] Japan, greatly restricting [the Eastern Axis’s] access to these critical commodities.²⁷ In December [the Imperialists] seized the initiative, launching coordinated assaults on Pearl Harbor, Hong Kong, Malaya and the Philippines.

[Axis] forces landed in southern Thailand and northern Malaya very early on 8 December 1941, opting to approach Singapore overland through Malaya. The British Chiefs of Staff Committee had considered this possibility in 1940 and concluded: “An advance down the Isthmus and across Malaya was fraught with difficulty and should be particularly vulnerable to air attack.”²⁸

Elaborating on this point, the Joint Planning Staff observed that the mountains in Malaya, together with “the rivers which flow in the valleys between them and the almost impenetrable jungle which covers the greater part of the country, form well nigh insuperable barriers to Communications”.²⁹

After the [Axis] landing, the Malayan administration issued reassurances, claiming that British forces were well prepared to handle the situation, and that [Imperial] Japan, “drained for years by the exhausting claims of her wanton onslaught on China”, was incapable of posing a serious threat.³⁰ A memorandum prepared by U.S. intelligence on 12 December 1941 continued to show unwarranted optimism about Britain’s capacity to resist [an Imperial] advance.

After describing the defences of Singapore (coastal artillery, anti‐aircraft batteries, barbed wire entanglements and pill boxes, and 50,000 troops), the document continued:

The “back door” approach via the Malayan Peninsula is protected by British, Indian, and Malay troops, reinforced by the Volunteers of the Straits Settlements and Malay States and the Johore Military Forces. There are probably more trained troops to the square mile in Malaya than in any neighboring country. The geography of Malaya is also a factor in its defense. The coastal plains average only about fifteen miles in width and their hollows are filled with mango swamps [sic, an error for mangrove swamps].

The mountain range which runs north and south […] is covered with dense jungle and vast areas are almost unknown, except to forestry workers and surveyors. Roads are few and heavily guarded, so that an invading army would be at the mercy of defenders securely hidden in the jungle.³¹

When this assessment appeared, the [Imperialists] were already enjoying considerable success using the “back door” approach. Units which came ashore in southern Thailand had crossed over to the west coast of the peninsula and on the 12th succeeded in dislodging the British from Jitra, a strong point about 15 miles north of Alor Star.

Additional forces had landed in Kelantan and were moving southward along the east coast, a more difficult undertaking because there was no coast road, although they were able to follow the eastern branch of the railway line through the jungle. The [Axis] quickly achieved air superiority, and the capture of British airfields in northern Malaya gave [it] facilities to support [its] ground forces.