There has been mounting frustration in Europe over Germany’s disinclination to send Leopard 2 battle tanks to Ukraine, or let allies donate their German-made Leopards to Ukraine to help it fight Russian invaders. Germany technically must approve sending the Leopards to Ukraine, but Polish Prime Minister Mateusz Morawiecki said Thursday that as far as Poland is concerned, “consent is secondary. Either we will obtain this consent, or we will do the right thing ourselves.”

“Evidence of the Russian army’s war crimes can be seen on television and on YouTube,” Morawiecki told Polish state news agency PAP in an interview published Sunday. “What more does Germany need to open its eyes and start to act in line with the potential of the German state?”

German Foreign Minister Annalena Baerbock told French TV Chanel LCI on Sunday that “if we were asked, we would not stand in the way” of Poland sending its Leopard tanks to Ukraine. Final assent must come from German Chancellor Olaf Scholz, CNN reports. German officials “know how important these tanks are” and “this is why we are discussing this now with our partners,” Baerbock told LCI. 

Scholz has said that Germany would not unlock that Leopards unless the U.S. agreed to send its Abrams tanks to Ukraine as well. The U.S. military, and tank experts, say the Abram tanks are too heavy and too hard to maintain to be effective in Ukraine. Modern tanks are one of Ukraine’s top asks from Western military donors. 

“Military experts disagree on how essential the Leopard 2 tanks are for Ukrainian troops, but the tanks have become a political symbol for whether Europe is willing to back Ukraine enough to win,” The Wall Street Journal reports. “Germany’s cautious approach to arming Kyiv, reflecting both domestic politics and a fear of Russian nuclear escalation, is coming under pressure from countries in Northern and Eastern Europe that feel a greater sense of urgency as Russia and Ukraine both prepare for expected offensives.”

The frustration with Berlin “has overshadowed Germany’s substantial deliveries of arms and ammunition,” the Journal adds. “It is one of Ukraine’s main military backers in Europe, along with the U.K., although the U.S. continues to dominate.”