Due to its weakened condition at the end of the war Britain lacked the resources to provide a force by itself and it wanted members of Commonwealth to help supply sufficient numbers to show the United States that it was still a major power.

[citation needed] Prime Minister Peter Fraser wanted the 5,000-strong contribution to be drawn from single male volunteers from the 2NZEF.

[5] The initial draft consisted of two infantry battalions—the 27th and 22nd Battalions—as well as the 2nd Divisional Cavalry Regiment, the 25th Field Battery, and the 5th Engineer Company along with supporting elements which included signals, transport, workshops and medical units.

The British Commonwealth Occupation Force (BCOF) was to be responsible for Hiroshima Prefecture as it contained a large port, Kure, and an adjacent airfield, Iwakuni.

Within the BCOF J Force was responsible for the largely rural Yamaguchi Prefecture and Mishima Island, both in the south of Honshu.

[10] The initial draft encountered uncomfortable living conditions and poor food, which they compared unfavourably with what they had experienced in Italy.

Because members of the BCOF were paid in pounds sterling whose exchange rate with the yen was set at an artificially low rate in an effort to slow inflation, this allowed members of the force to make money on the black market supplying Japanese with basic goods such as food and soap.

[12] Boredom was also initially a major problem, but as non-fraternisation rules were progressively relaxed high rates of venereal disease developed.

As such, J Force's policing duties included monitoring black market groups and also large gatherings of people on public occasions and generally keeping order until civilian government could be re-established.

[16] Initially located in southern Honshu at the former Japanese naval air base at Iwakuni, the squadron undertook armed air patrols designed to protect armament and bomb dumps, identify locations of hidden ammunition, and check schoolyards for forbidden military parades.

[17] The squadron stayed in Japan for second year despite lacking a third of its ground staff due to the New Zealand Treasury Department refusing to fund recruiting advertisements.

[22] Once a week a Dakota departed on the 20,000 km return flight between Whenuapai and Iwakuni carrying supplies and personnel between the two destinations.

[citation needed] When Great Britain and India withdrew from the BCOF in 1947 enthusiasm for New Zealand’s ongoing involvement waned.