More than ever before, the conflicts in Ukraine and Syria are coming together. The calculations in the Kremlin and in Turkey’s presidential palace are especially complicated now as the two capitals must consider three different angles. First, in a month the United Nations Security Council must vote to approve continued humanitarian aid deliveries from Turkey into Idlib and north Aleppo provinces. It is a vital Turkish national interest that the three million Syrian civilians in that region not try to enter Turkey.

The Russian deputy ambassador in New York two weeks ago warned Moscow might veto the extension of the cross-border aid operation, thus threatening those civilians. However, a group of Russian experts I met at the end of May acknowledged that Russia problems with the Ukraine war will lead it to avoid a new, bitter fight with Turkey about northwest Syria now.

The American ambassador to the United Nations just visited southern Turkey and from there she warned Ankara that the Biden administration supports ceasefires in Syria. In particular, Washington aims to prevent escalation in northern Syria that would shift Syrian Kurdish YPG militia fighters from operations against ISIS to fighting against Turkish forces and their Syrian National Army allies.

The Turkish response to Washington is that already the YPG is violating the north Syria ceasefire and using the towns of Tell Rifaat and Manbij as launch points for attacks against Turkish and Turkish allies.

In theory, Erdogan had an agreement with Russia in 2019 for Russia to move YPG elements out of these two towns, but the Russians didn’t uphold their pledge. With the Ukraine war, Russian forces have left the area, and the Iranian Revolutionary Guard Corps has taken positions close to the YPG. (Remember that the Iranians also are cooperating with the YPG mother organization, the Kurdish PKK group in Sinjar in Iraq.)

The Turks do not want PKK or Iranian forces near their southern border. Thus Erdogan is promising to seize Tell Rifaat and Manbij in a fourth Turkish military invasion of Syrian territory. Erdogan needs Russian agreement not to use its warplanes against Turkish forces. Erdogan also hopes to secure new American warplanes, and thus he wants to avoid a new crisis with Washington. The timing of his operation, therefore, is a question.

The final calculation involves Russia, Turkey and the United States and NATO. After the Russian aggression against Ukraine, Sweden and Finland will present their formal applications to join NATO at the alliance summit in Madrid at the end of June. Due to domestic politics related to the Kurdish issue, Erdogan is vowing to block their entry and Turkey has a veto.

Erdogan demands Sweden and Finland remove a ban against arms exports to Turkey that the two countries imposed after the 2019 Turkish invasion of northeastern Syria that hindered YPG consolidation in northeast Syria. Helsinki has hinted that it could accept a compromise on the Finnish embargo. However, a new Turkish invasion of northern Syria will make it harder for Finland and Sweden to give concessions to Erdogan. At the same time, the Turkish President must understand that Russian President welcomes delays to the NATO expansion. The timing of steps is important.

The Syrian war and Turkish actions even affect the stability of the Swedish government in Stockholm. Domestic politics in Sweden may lead to a confidence vote for the government’s Interior Minister. The fate of the minister appears to depend on the vote of an independent deputy of Kurdish origin. This deputy rejects Turkish pressure on Sweden because of the Kurdish issue and she insists that Stockholm improve relations with the YPG. If the Swedish parliament brings down the Interior Minister, the Swedish prime minister has promised to resign and the Swedish government will fall ahead of new elections in August. This will further delay Sweden joining NATO.

Sweden is not going to expel Kurdish refugees and break all ties with Kurdish political groups to satisfy Erdogan. In addition, Washington is annoyed that Turkey is delaying the two Nordic states’ entry into NATO and is unlikely to take initiatives to appease Erdogan.

In a meeting last month with a group of distinguished Turkish experts and politicians I mentioned that some western politicians wonder if NATO should expel Turkey in order to simplify admission of Finland and Sweden. My Turkish colleagues objected angrily. For them, the problem is NATO ignoring Turkish security concerns. The pressure from NATO on Ankara will grow, and an unhappy Erdogan will have to accept difficult compromises. In the end Sweden and Finland will join NATO. The arguments about the Kurdish issue and future strategy in Syria guarantee that Putin will find new opportunities to exploit divisions inside the Atlantic alliance.