If there will be a new economy update that will allow the option of attacking and defending sea convoys or land caravans (which would be fantastic to improve the gameplay at a geopolitical tactical level), the presence of "stocks" of resources would initially serve to store strategic or luxury resources (these could have their own system), where one could "store" bronze, iron, saltpeter, oil or uranium, etc. and thus prepare for a war where units are lost and can be replaced. 


In order to lead the war not only to capture cities but also points of valuable resources or sink routes (foreign and internal trade) and thus put the balance in your favor.