On 27 March 2007 in Moscow, Latvian Prime Minister Aigars Kalvītis and Russian Prime Minister Mikhail Fradkov signed the Latvia–Russia state border treaty. It legally fixed a border that, since the Soviet occupation period, had de facto left the town of Abrene and six former Abrene district parishes on the Russian side. The treaty triggered sharp constitutional debate in Latvia, but the Constitutional Court later found that it did not violate Article 3 of the Constitution.

The Abrene question was one of the most sensitive intersections of foreign policy and constitutional law in restored Latvia. Concluding the border treaty helped settle a long-delayed interstate border issue while again bringing the consequences of occupation and the continuity of the Latvian state into public debate.