China’s decision to restrict critical mineral exports will hit vital sectors in the European Union’s effort to decarbonize its economy, and demonstrates the limits of western aspirations to shift supply chains beyond the reach of policymakers in Beijing.

China is the largest global producer of the two minerals, gallium and germanium, which will be subject to export restrictions next month and that are crucial to the semiconductor, telecommunications and electric-vehicle industries. The EU gets 71% of its gallium from China and 45% of its germanium.

The move comes weeks after the EU unveiled a new economic security strategy, which seeks oversight of critical technology exports and may curb outbound investments in the name of national security. The proposal is part of a growing push within the bloc to strengthen security tools as countries such as China and Russia increasingly use trade and the control of critical supply lines to advance political and even military goals.