Dragon's teeth fortifications, pyramidal anti-tank obstacles, are seen during a press tour to present military reinforcement measures near the border of Latvia with Russia, on August 16, 2024 in Karsava, Latvia. Poland and the Baltic states -- which all have borders with Russia -- have begun fortifying their eastern borders. The four EU members are staunch allies of Ukraine, which has been fighting a fully-fledged Russian invasion for more than two years. "Building a defence infrastructure system along the EU external border with Russia and Belarus will address the dire and urgent need to secure the EU from military and hybrid threats," the four EU members said in a joint letter to Brussels in June. (Photo by Gints Ivuskans / AFP)