Although the London postmark date is illegible, this cover was presumably sent after mid-April 1975 when Phnom Penh fell to the Khmer Rouges and the Cambodian infrastructure had ground to a halt. The cover is notable for its hand stamp marking "Services Suspended to Cambodia". What other countries applied this type of marking?
Phillippe Drillien writes that France used markings for mail bound to Cambodia. He believes this type of marking was used twice. First in 1970 when Sihanouk has been abdicated, and a second time, in 1975, after the fall of Phnom Penh.