Stephen Sackur speaks to Leopoldo Lopez, a key leader of Venezuela’s opposition. Once a political prisoner, now in exile in Spain, his efforts to topple the socialist regime led by Nicolas Maduro have been thwarted. Has Venezuela’s pro-democracy movement been outmanoeuvred?

Stephen Sackur speaks to Ukraine’s foreign minister, Dmytro Kuleba. The war with Russia has hit a winter stalemate, but what will spring bring? From battle tanks to air defences, Ukraine wants more help from its allies. Is Western wavering undermining Kyiv’s strategic options?

Stephen Sackur speaks to Ruben Vardanyan, state minister of the disputed enclave of Nagorno-Karabakh, run by ethnic Armenians but surrounded by Azerbaijan and the subject of years of conflict. The Armenians have traditionally been backed by Russia, but is Putin a reliable ally?

Brazilian President Lula must figure out whether another assault on government institutions is likely, and hold those responsible to account. All of that while he faces a mountain of economic, social and political challenges. How close is Brazil to being ungovernable? Stephen Sackur interviews Celso Amorim, formerly Brazil's foreign minister, now President Lula’s foreign policy advisor.

Stephen Sackur is in Geneva to speak to Ngozi Okonjo-Iweala, director general of the World Trade Organization. Her job is to maximise free and fair trade across the world. How is that possible in this age of big power tension and increased suspicion of globalisation?