Было очень сложно убедить президент

Было очень сложно убедить президента в технической невозможности начала этой операции.

Результаты (английский) 1:

It was very difficult to convince the President of the technical impossibility of the beginning of the operation.

Результаты (английский) 2:

It was very difficult to convince the president of technical impossibility of launching the operation.

Результаты (английский) 3:

It was very difficult to convince the president of the technical impossibility in the beginning of the operation.