The Russian invasion of Ukraine has significantly impacted the ability to accurately describe Arctic conditions, leading to a biased view of Arctic change. This study evaluates the representativeness of the INTERACT research station network, which is the largest high-latitude research station network, with or without Russian stations. Excluding Russian stations markedly reduces the network's representativeness, with some biases comparable to the expected climate change impacts by the end of the century. The geopolitical conflict has hindered transnational collaboration on Arctic issues, particularly affecting the Arctic Council, which is one of the eight Arctic nations. Russia, the largest Arctic nation, has been excluded from the Arctic Council since the invasion of Ukraine. The Arctic is rapidly changing, with many changes having global consequences. While some climate indicators can be estimated remotely, much of the understanding of Arctic change relies on in situ data from research stations. The exclusion of Russian stations from the INTERACT network has led to a loss of representativeness, particularly in regions like Siberia, which is under-represented. This has resulted in biases in key ecosystem variables such as vegetation biomass, net primary productivity, and heterotrophic respiration. The loss of Russian stations has also reduced the ability to monitor the Arctic biome, affecting the ability to track global implications of thawing permafrost and biodiversity changes. The study used eight Earth system models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to assess the representativeness of the INTERACT network. The results show that even with all Russian stations included, the network is biased for some ecosystem variables and is not fully representative of the Arctic. The exclusion of Russian stations further exacerbates this bias, particularly in the boreal zone, where many stations are lost. The study highlights the importance of maintaining a comprehensive and representative research infrastructure for the Arctic to better understand and predict climate change impacts. The exclusion of Russian stations has reduced the ability to monitor the Arctic biome, affecting the ability to make informed management and conservation decisions. The study calls for continued efforts to establish and improve a research infrastructure that is representative of the entire Arctic.The Russian invasion of Ukraine has significantly impacted the ability to accurately describe Arctic conditions, leading to a biased view of Arctic change. This study evaluates the representativeness of the INTERACT research station network, which is the largest high-latitude research station network, with or without Russian stations. Excluding Russian stations markedly reduces the network's representativeness, with some biases comparable to the expected climate change impacts by the end of the century. The geopolitical conflict has hindered transnational collaboration on Arctic issues, particularly affecting the Arctic Council, which is one of the eight Arctic nations. Russia, the largest Arctic nation, has been excluded from the Arctic Council since the invasion of Ukraine. The Arctic is rapidly changing, with many changes having global consequences. While some climate indicators can be estimated remotely, much of the understanding of Arctic change relies on in situ data from research stations. The exclusion of Russian stations from the INTERACT network has led to a loss of representativeness, particularly in regions like Siberia, which is under-represented. This has resulted in biases in key ecosystem variables such as vegetation biomass, net primary productivity, and heterotrophic respiration. The loss of Russian stations has also reduced the ability to monitor the Arctic biome, affecting the ability to track global implications of thawing permafrost and biodiversity changes. The study used eight Earth system models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to assess the representativeness of the INTERACT network. The results show that even with all Russian stations included, the network is biased for some ecosystem variables and is not fully representative of the Arctic. The exclusion of Russian stations further exacerbates this bias, particularly in the boreal zone, where many stations are lost. The study highlights the importance of maintaining a comprehensive and representative research infrastructure for the Arctic to better understand and predict climate change impacts. The exclusion of Russian stations has reduced the ability to monitor the Arctic biome, affecting the ability to make informed management and conservation decisions. The study calls for continued efforts to establish and improve a research infrastructure that is representative of the entire Arctic.