Some countries have legalised cannabis, often with the hope of kick-starting a lucrative new source of tax revenue - but just how profitable has it been? Aside from a few fact-finding trips, the prospect of legalising cannabis is not on the political agenda here in the UK - but could it be missing out? Advocates say it's a bad call to let criminals continue to profit when legal businesses and the government could reap the financial rewards instead. Opponents counter that no amount of money is worth the associated public health risks. But in the past decade countries including Canada, Malta, Uruguay and parts of the United States have decided to embrace the so-called green rush. But how is it working out for them economically and what lessons could other places considering legalisation learn? Reporter Datshiane Navanayagam talks to: Christopher Snowden, Head of Lifestyle Economics at the Institute of Economic Affairs Adam Spiker, executive director of a cannabis trade association in California Amanda Chicago Lewis, a US based investigative reporter covering cannabis Laura Schultz, executive director of research at Rockefeller Institute of Government in New York Rishi Malkani, Cannabis Leader at Deloitte Charlotte Bowyer, Head of Advisory at Hanway Associates Producer: Ben Carter Editor: Richard Fenton-Smith Production co-ordinators: Helena Warwick-Cross and Maria Ogundele Sound engineer: James Beard

In late February, three days after the Russian invasion of Ukraine, the German Chancellor Olaf Scholz made a landmark speech in the German parliament, the Bundestag. The invasion, he declared, represented a 'Zeitenwende' - a turning point. The speech has been much discussed since - was Mr Scholz referring simply to the fact of the invasion, or to the way Germany needed to respond to it? The speech contained a number of policy statements, the boldest of which was the commitment to set up a 100 billion Euro fund to re-equip Germany's outdated armed forces. The question now is whether Germany will live up to Mr Scholz' promises, or will the cultural, political and economic bonds that have tied Germany and Russia together get in the way? Presenter: Caroline Bayley Producer: Tim Mansel

Digital advertising fuels the digital economy, but is it all based on smoke and mirrors? Ed Butler investigates what some claim is a massive collective deception - a trillion dollar marketing pitch that simply does not deliver value to any of those paying for it. He asks, do online ads actually work, or could it be that some of the biggest names in global tech are founded on a false prospectus?

Arguments over the value of nationalism seem to have been raging for centuries, even though the nation state as we know it has only become widespread in the last two hundred years. In this programme, David Edmonds tracks the emergence of the nation state and the debate surrounding it. From post-colonial Ghana to contemporary Britain, we hear what nationalism has meant to different people in different contexts, as well as the social and philosophical principles that underlie it. Contributors: Professor Michael Billig, Emeritus Professor of Social Sciences at Loughborough University, Professor Richard Bourke, professor of the history of political thought, University of Cambridge. Elizabeth Ohene, former Minister of State in Ghana. Dr Sandra Obradovic, Lecturer in Psychology, The Open University. Professor Tariq Modood, director of the Bristol University Research Centre for the Study of Ethnicity and Citizenship. Dr Sarah Fine, Senior Lecturer in Philosophy, University of Cambridge Producer: Nathan Gower Studio Manager: James Beard Editor: Richard Fenton-Smith Production Co-ordinators: Maria Ogundele and Helena Warwick-Cross

As Russia’s brutal war with Ukraine enters its fourth month, Edward Stourton asks who Russia's allies and friends are and looks at the nation's influence overseas. While President Putin has made no secret of his belief that Ukraine should be part of a “greater Russia”, what is less apparent is how far Russia’s influence is spreading in other parts of the world. These include sub-Saharan Africa, Latin America and the Middle East. With the West having left a vacuum in parts of Africa, President Putin has been able to offer military help in unstable countries such as Mali and the Central African Republic. This follows Russia's intervention in Syria's civil war on the side of Bashar Al-Assad's government, with implications for the wider geopolitics of the region. And in Latin America, Russia is accused of using soft power tactics through its media channels to polarise society and spread anti-US and anti-Western propaganda. Edward Stourton asks to what extent this shows that Russia is trying to rebuild the old Soviet-US spheres of influence of the Cold War. Producer: Caroline Bayley Editor: Richard Fenton-Smith Sound Engineer: James Beard Production Coordinators: Maria Ogundele and Helena Warwick