UK Prime Minister Keir Starmer faces significant domestic and international challenges as he seeks to implement his agenda. The unexpected events of the COVID-19 pandemic and the riots in UK urban areas have already tested his government. The biggest international challenge could come from a second Donald Trump US presidency, which could create disagreements and obstacles in areas such as economics, environment, and defense. Starmer's goal of redefining the UK's polity and economy will require more than a single term in office. He must balance foreign policy efforts with pushing ahead with his domestic agenda.