What if France had built a fully effective Gloire and Britain could not answer with a massively superior Warrior?
Short answerBritain would use its superior industrial capacity to outbuild France, producing an early ironclad arms race and possibly a serious war scare.
NotesThe counterfactual gives France a more convincing first ironclad and removes some of Warrior's qualitative advantage. Britain would respond with its greater shipbuilding capacity, turning the competition into an earlier major naval race. A war scare or even an Anglo-French conflict also becomes plausible if Napoleon III handles the rivalry badly. The ship-design contest could therefore carry industrial and diplomatic consequences.