The former prime minister was forced to step down in July after a series of scandals but has remained as an MP and remains steadfastedly supportive of Ukraine. Political reporter @alixculbertson Please use Chrome browser for a more accessible video player Boris Johnson has shown his focus remains on the war in Ukraine since he stepped down as prime minister. In an exclusive interview for Sky News' Ukraine: A Modern War programme, Mr Johnson spoke about the war, Vladimir Putin, the West's response, his successor and his admiration for Joe Biden. However, he refused to dwell on the circumstances surrounding his departure this summer. Mr Johnson resigned as PM in July - and returned to the back benches in September after Liz Truss became the new prime minister. A lot has happened in the world of politics since then - he has had two successors and the economy went into freefall but his focus remains on Ukraine. 'Pivotal moment' for the world On whether President Putin might use a nuclear w