Complex sentence: From 1995 to 1998 he was in the United States and spent a year as an International Fellow at Harvard University and later working at the British Embassy in Washington, where he headed the Foreign and Defence Policy team.
Split into simpler sentences: From 1995 to 1998 he was in the United States. He spent a year as an International Fellow at Harvard University and then joined the British Embassy in Washington where he headed the Foreign and Defence Policy team.