What was the economic necessity of the unification of Germany and Italy?

In the unification of Italy and Germany, you can find a lot in common, but there were also different features, of course. If we talk about general features, then the most important here can be called liberal and ideological, as well as republican and church ones. In each of these countries there were different currents that advocated unification. But the economic component was to create a powerful state that would be able to protect its lands from attacks and plunder. It was also supposed to lead to the growth of the industry.