What predominates in this passage is the idea that France loses the total value of the products she imports from abroad.

Frédéric Bastiat
Economic Sophisms Third Series

Once again, at the root of the fallacious reasoning that is here exposed by Bastiat is the belief that imports constitute the cost of international trade while exports would constitute de benefits of it. Of course, the reverse is true.

It is here within the frame of discussions about the legitimacy of colonisation that this theme is popping up. Indeed, we can see through the discussions in parliament for which some excerpts are reported here that the theme of political economy that is not very well understood by non-economists, be they MPs and generals, was used to argue in favour of colonisation. Here, Bastiat who was fiercely against colonisation shows the errors that these arguments imply, be it from a human point of view as well as an economic point of view.

In any case, to invade and colonise a country so that what is sold and bought can be counted as internal trade instead of international trade is an argument that makes absolutely no sense from an economic point of view.