Russia’s war against Ukraine in February 2022 was the end of the Arctic cooperation between states and others as we knew it, despite the fact that Russia’s illegal actions are not occurring in the Arctic region. Russia’s attack on Ukraine caused pronounced security fears and responses, particularly from the European and North American countries, including the other Arctic states. This naturally affected Arctic cooperation because it is precisely in the Arctic region that Russia is such a vastly central actor. For example, the region’s pre-eminent inter-governmental forum, the Arctic Council, is struggling to continue its activities in full, as the seven western Arctic states paused participating in meetings held in and activities involving Russia. On the other hand, the first in-person meeting of the Conference of the Parties (COP) under the Central Arctic Ocean (CAO) fisheries agreement in late November 2022 successfully adopted its COP Rules of Procedure by consensus, including Russia. The purpose of this article is to investigate how adversely Arctic international cooperation in inter-governmental forums and treaties has suffered due to the Ukraine war, utilising a qualitative research methodology to collect internal and sensitive information from key informants. In particular, the article aims to find an answer to the following question: In which types of Arctic inter-governmental structures have the states been able to continue the cooperation and for what reasons? The hypothesis that will be tested in this article is whether treaty-based cooperation has fared better than cooperation founded on soft law. This article will flesh out the current state of Arctic cooperative frameworks and actual cooperative activities under them, analysing three soft law-based cooperative frameworks, including the Arctic Council and several treaty-based cooperative frameworks, such as the CAO fisheries agreement and Arctic Science Cooperation Agreement. This article is based on the facts as of 22 February 2023.