Take the TTIP and TPP agreements currently under negotiation and ratification.
These dubious treaties represent a smash and grab on behalf of, and to protect the profits of, transnational vested interests (large corporations esp. intellectual property rights holders), enforced in part by the contingency of US military and political alliance, and interpreted on behalf of the citizens of different countries globally through a false lens of "national interest".
They include surprising, secretly drafted concessions of sovereignty that should be inalienable from the people of individual democracies.
A typical citizen's interests are not in a clear sense the "national interest". The "national interest" usually means the interests of the legislative enclosure's strongest capital alliance against other, similar alliances globally.