Why has Turkish president Recep Tayyip Erdogan poured cold water on announcements by Finland and Sweden that they wish to join Nato?
The ambitions of the two countries to join have been warmly welcomed elsewhere in the alliance, as they are seen as like-minded countries that are a natural fit, with strong militaries that will add to Nato’s defence.
Adding a new country requires the unanimous support of all existing members of the alliance, and a June Nato summit in Madrid has been earmarked as the start of the accession process.
The legal basis of Nato is a treaty that lays out its foundational principle of collective defence: that an attack on one member is considered an attack on all. For a new country to join, each existing member must ratify an amendment increasing its membership, and some states require parliamentary votes for this.
In the past, this process has taken roughly a year, a period during which officials say Finland and Sweden would be considered defacto members, already included within the defence umbrella.
It all gives Turkey leverage. And Erdogan will use it. There are a number of reasons for him to do this.
Firstly, using leverage is what he does: see for example his repeated use of the threat of letting more people cross into the EU through its border to extract more financial aid.
There are good domestic political reasons too. A general election is due in 2023. Erdogan’s position will probably cause important people to fly to Ankara to court and persuade him, burnishing his image as an important figure at the centre of events on the international scene, and achieving his ambition to assert Turkey’s status as an important power.
Is he doing a favour to Moscow? Turkey has spoken in support of Ukraine’s sovereignty and sold it the now-famous Bayraktar drones for its defence (there is a viral Ukrainian song about them if you haven’t heard it). At the same time however, it has also sought to retain strong relations with Moscow and establish itself as a mediating power, declining to join in with western sanctions, and hosting peace talks in Istanbul.
This approach stretches back further than the outbreak of the war. A year ago, Turkey insisted on watering down a Nato statement condemning the forced landing of a Ryanair flight by Russian ally Belarus, preventing the alliance from expressing support for sanctions or calling for the release of political prisoners.
It reflects Turkey’s status as a somewhat awkward Nato member in recent years as it accumulated reasons to feel unloved.
Erdogan said he was opposed to Finland and Sweden joining because "Scandinavian countries are like terrorist groups' guesthouses". This points to a long-running grievance: the support of Nato allies to Kurdish militias in their fight against Islamic State in Syria, and perceived western "softness" on Kurdish militancy more generally.
It touches on a security concern with deep roots in the Turkish state, which has a Kurdish minority population and has fought aspirations for Kurdish autonomy going back decades.
In this context, the support of various Nato allies for Syrian Kurds was resented by Turkey, which views armed Kurdish groups as a threat to security on its southern border that could have domestic repercussions.
Abroad, Turkey has long accused the West of failing to crack down on diaspora supporters of the Kurdistan Workers’ Party, which is officially deemed a terrorist group by Turkey, the EU, the US and others.
Blocking Finland and Sweden from joining Nato is an opportunity for Erdogan to attempt to get the West to take these concerns more seriously and to get Washington on the line.
"Was Erdogan trying to put pressure on the US Congress for those F-16s that Ankara wants to purchase? Was this really about more money for Syrian refugees in Turkey? Or did he really want Gulenists [supporters of the cleric and former Erdogan ally Fethullah Gulen] or PKK sympathisers extradited to Turkey?" asked senior policy fellow Asli Aydintasbas in an analysis for the European Council on Foreign Relations.
“It is unlikely that Erdogan had one specific policy goal in mind, but he will no doubt be expecting to be cajoled, persuaded, and eventually rewarded for his co-operation, as in the past.”
There’s no guarantee, but officials are hopeful that Erdogan can be persuaded to drop his opposition, with the right offer.