Rubuta ci gaba don wannan sakin layi - Bayan barkewar Yaƙin Duniya na II, gwamnatin Faransa ta aika Rapkine zuwa London a watan Janairun 1940, a kan wani aikin hukuma don tabbatar da samar da kwal don masana'antar Faransa da dalilai na soja. Duk da yake a Ingila, ya taimaka wa James Crowther wajen ƙirƙirar Anglo-French Society of Sciences don tabbatar da hadin gwiwar kimiyya tsakanin ƙasashen biyu. A watan Yuni na shekara ta 1940, bayan da Faransa ta miƙa kai ga Jamus
, Rapkine ya yi kira ga Society don taimakawa masana kimiyyar Faransa su sami mafaka a Burtaniya, amma an rushe Society lokacin da tashin hankali tsakanin Faransa da Ingila suka dakatar da hadin gwiwar kimiyya. Rapkine da Henri Laugier sun bar London don ci gaba da kokarinsu a Amurka.