There will be no grace period for Germany's new defense minister who takes office as pressure is piling on Berlin to send battle tanks to Ukraine and to upgrade its dilapidated armed forces in the face of Europe's biggest conflict since World War II.

Boris Pistorius, 62, will take over on Thursday, just a day before a major arms pledging conference at the U.S. military base of Ramstein in western Germany, succeeding Christine Lambrecht, who quit on Monday following a series of blunders. It will befall the outgoing Lower Saxony interior minister to explain to partners whether Berlin will deliver German-made Leopard battle tanks to Ukraine or at least allow others to do so, a decision seen as key to Kyiv's efforts to repel Russian troops. This week, Britain raised the pressure on Berlin by becoming the first Western country to send Western tanks, pledging a squadron of its Challengers, but the Leopards are seen as the best choice to supply Ukraine with a large-scale tank force.

Germany's reticence has raised questions about how serious it is about the "Zeitenwende," or new era of more assertive foreign policy backed by more military spending, that Chancellor Olaf Scholz announced on Feb. 27, just days after Russia's invasion of Ukraine.