M274 Mechanical Mule ir pēckara laikmeta amerikāņu vieglais transporta līdzeklis. Pirmie šī transportlīdzekļa eksemplāri parādījās 1950. gadu vidū, un sērijveida ražošana turpinājās 1956.–1970. Tās gaitā tika uzbūvēti aptuveni 11 300 šāda veida transportlīdzekļi. Pamata versijā piedziņu nodrošināja viens Willys AO4-4-53 dzinējs ar 16 ZS.
M274 transportlīdzeklis tika izstrādāts, lai papildinātu Willys Jeep un Dodge M-37 transportlīdzekļus desantnieku un kājnieku vienībās. M274 galvenokārt tika izmantots ložmetēju, mīnmetēju un kravu pārvadāšanai, kas sver līdz 250 kilogramiem. To izmantoja arī ievainoto evakuācijai no kaujas lauka, kā arī līdz 7 karavīru transportēšanai. Šāda veida transportlīdzekļi tika plaši izmantoti Vjetnamas karā (1964 / 1965-1975), kura laikā tiem bieži tika uzstādīti bezatsitiena lielgabali un ložmetēji. M274 kalpoja ASV armijā līdz 80. gadiem.
The Vietnam War (1964 / 1965-1975) is a conflict fought between the government of South Vietnam, supported very intensively (economically, politically, militarily) by the United States, and North Vietnam, supported by the USSR and the PRC. Due to the very difficult terrain in Vietnam (jungle, numerous watercourses and canals, hills), the basic type of armed forces quickly turned out to be infantry, especially light infantry with high mobility and aeromobility. The primary shooting weapon of the American infantryman in Vietnam was initially the 7.62mm M14 semi-automatic rifle. However, already in 1964, the 5.56 mm M16 automatic carbine (initially as the XM16E1) was experimentally introduced, which from 1966 began to be the basic weapon of the US infantry, and from 1967, improved examples of the M16 A1 were delivered. The weapon, especially in the initial production batches, was not fully developed and, besides, it required very careful cleaning and was highly susceptible to dirt and jammed easily. In addition, 40 mm M79 grenade launchers were used. The M72 and M72A1 LAW missiles were rarely used. On the other hand, the Browning M2 heavy machine guns and the M60 heavy machine guns were used on a large scale. During the Vietnam War, the platoon turned out to be the basic tactical unit of the US infantry. Its structure in line, light and airborne infantry was almost identical. The platoon consisted of a staff headed by a lieutenant or second lieutenant and a sub-unit assigned with an artillery observer, a paramedic and a radio operator. His main strength was three shooting teams of 10 soldiers each. In addition, there was a heavy weapons team with two M60 Rkm-guns and two M67 recoilless guns. It is worth adding that the above-mentioned organization was a full-time one, and in the realities of the war the full-time job often differed from the realities of the battlefield.