Be interesting to see some Pakistani members chime in, since amidst the ongoing war in Ukraine and impending kinetic action against Iran, Pakistan declaring war on the Taliban just caught me out of left field.
Conventionally, if the Taliban actually chose to fight Pakistan on those terms, the results are obvious. Despite all those propaganda videos of their fighters in tactical gear, they are a guerilla force at heart with minimal armor and never even figured out how to pilot all those helicopters the US left behind. This just leaves open questions.
Now that "open war" has been declared, how far does Pakistan intend to go? Full invasion of Afghanistan? Wearing down the Taliban with airstrikes so that they accept Pakistan's terms? While the conventional fighting against Taliban forces goes on, what of Pakistan's own restive Pashtun regions? Could a conflict stir up further violence in that region?
Obviously if Pakistan plays its cards right this could work out well as Pakistan can obtain true strategic depth, but the spectre of this conflict amidst American action against Iran is putting quite the plate on China's table with respect to its Western flank.