Complex sentence: His pleaded a defence of duress, claiming that he had no choice as the terrorists had threatened to kill him if he did not follow through with their reque of the defence he wanted to testify about these conversation he had with the terrorists.
Split into simpler sentences: His pleaded a defence of duress, claiming that he had no choice as the terrorists had threatened to kill him if he did not follow through with their requests. As part of the defence he wanted to testify about these conversation he had with the terrorists.