President Biden's decision to allow Ukraine to hit Russia with American long-range missiles has prompted scorn in Moscow. What difference will the move by the outgoing administration make - and might other Western allies follow the US' lead?

Also in the programme: We'll hear from Delhi, the Indian city which gasps under unrelenting toxic smog; and he leaders of the world's most powerful countries meet in Brazil - but are they just marking time until Donald Trump returns?

(Photo shows a file photo of a missile from the Army Tactical Missile System, a surface-to-surface ballistic system, similar to what Ukraine is going to use. Credit: White Sands Missile Range Public Affairs)