Turkey’s ambassador joined all 30 Nato allies in signing accession protocols for Finland and Sweden in Brussels on Tuesday, despite a simmering row over Swedish extradition of Kurdish “terrorist” suspects to Turkey. The Nordic countries still need ratification by all 30 national parliaments to become full members. But Turkish president Recep Tayyip Erdoğan has demanded Sweden must first extradite 73 Kurds, causing a political backlash in Stockholm.