Vladimir Putin knows how to probe for weakness in the West. With his troops building up on the Ukrainian border, Russia’s president is testing the unity of NATO. In particular, he is putting pressure on Europe’s eastern flank. How will nations once in the Soviet orbit respond? Stephen Sackur speaks to Kiril Petkov, Prime Minister of Bulgaria, which Moscow says must not host a NATO military presence. This is a big test for a new prime minister in the EU’s poorest country. Is Bulgaria ready to stand up to Russia?

Republican Congressman Michael McCaul accuses President Biden of failing to stand up to the challenge of Vladimir Putin in Ukraine. After four years of Donald Trump, are Republicans credible when they condemn Biden for foreign policy failure?

(Photo: Congressman Michael McCaul appears on Hardtalk via videolink)

Stephen Sackur talks to George Takei, forever famous as Lieutenant Sulu in Star Trek. Interned as a child in the United States for being of Japanese origin, he now campaigns for gay and immigrant rights. Do the values of Star Trek still resonate?

Stephen Sackur speaks to the longtime leader of France's far right, Marine Le Pen. She's hoping to win the French presidency for her party, National Rally, in elections this spring. But the far right is now divided, and rivals accuse her of going soft in the defence of French civilisation. Have her efforts to detoxify her party’s image backfired?

Russian forces continue to gather close to Ukraine’s eastern and northern borders, and still the world waits to see what Vladimir Putin’s end game is. If the goal is to wring security concessions out of the US and its Nato partners, does he have any chance of success? Stephen Sackur speaks to Gabrielius Landsbergis, who is foreign minister of Lithuania and on the frontline of tensions between Russia and Nato.

Stephen Sackur speaks to comedian and writer Bassem Youssef. He made his name and won an audience of tens of millions with a satirical comedy show during Egypt’s popular uprising more than a decade ago. But the revolution quickly morphed into authoritarianism and Youssef fled to the US, taking his gift for comedy with him. Did he, and do we still, expect too much from political satire?

The decisive victory by Gabriel Boric, the left-wing candidate, in Chile’s recent elections has reset the button on the country’s political path. He defeated the right-wing presidential contender in a result which observers believe may be replicated when other Latin American countries go to the polls this year. Zeinab Badawi speaks to Isabel Allende, the acclaimed Chilean writer whose uncle was Salvador Allende, the left-wing Chilean leader removed in a coup in 1973. Isabel Allende has lived in four Latin American countries and knows the continent well. How does she view current trends in South America?

What is the galvanising force behind transformational economic change? Capitalism encourages us to look to the raw power of markets as the driver of innovation. But is that really true? Stephen Sackur speaks to the economist Mariana Mazzucato. Her faith in the transformational power of the proactive state has made her the go-to adviser to a host of governments. Does her "moonshot" economics ignore some earthly realities?

Stephen Sackur speaks to Hong Kong Legislative Councillor Dominic Lee Tsz-king, a high profile defender of Beijing’s increasingly tight grip on the territory. With China’s increasing crackdown in the city and pro-democracy activists arrested, exiled or cowed into silence, has "one country, two systems" become "one country, one system"?

HARDtalk’s Stephen Sackur speaks to the adviser to Iran’s negotiators in Vienna, Mohammad Marandi. Time is running out for negotiators trying to break the impasse between the United States and Iran and revive the deal curbing Tehran’s nuclear ambitions. Iran is still enriching uranium; the Biden administration is talking of giving up on the current diplomatic track. If a nuclear deal can’t be done, how real is the danger of a catastrophic war in the Middle East?