BERLIN — German Chancellor Friedrich Merz is facing rising opposition — but this time it’s from within his own conservative ranks. A group of 18 young lawmakers in Merz’s conservative bloc are threatening to stop a pension reform bill put forth by the chancellor’s coalition government, arguing the benefits pledged in the agreement aren’t sustainable and “cannot be justified to the younger generation.” The revolt has turned into a test of Merz’s authority and the durability of his relatively