What could Trump's 'America First' agenda mean for US foreign policy?

A new poll suggests Democratic nominee Kamala Harris has a slight lead over her Republican rival Donald Trump. Observers say US foreign policy is in for a shake-up, regardless of who wins the November presidential election. What could Mr Trump's 'America First' agenda mean for policy towards China, the Indo-Pacific, the Mideast and Russia? And the bigger unknown -- how might his running mate, JD Vance, impact his approach? Benji Hyer takes a look.