ɪt wʌz sˈæŋkʃənd ænd plˈænd baɪ ðə dʒˈɜːmən sˈiːkɹᵻt sˈɜːvɪs ɐbwˈeɪɚ ænd ˈɛksᵻkjˌuːɾᵻd səksˈɛsfəli ɪn mˈeɪ nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi.
It was sanctioned and planned by the German secret service (Abwehr) and executed successfully in May 1940.