@mebune,
The quintessential Adam Smith, which features in every introductory text on economics and in countless op-eds using laissez faire philosophy to argue against government regulation of international trade, is his famous "invisible hand" concept.
Ironically, this is based on the presumption that nationalism is so obviously in the individual interest that the tariffs, subsidies and other protectionist measures that were common practice by all developed nations of Smith's day (and indeed well into the twentieth century) were superfluous:
" As every individual, therefore, endeavours as much as he can both to employ his capital in the support of domestic industry, and so to direct that industry that its produce may be of the greatest value; every individual necessarily labours to render the annual revenue of the society as great as he can. He generally, indeed, neither intends to promote the public interest, nor knows how much he is promoting it. By preferring the support of domestic to that of foreign industry, he intends only his own security; and by directing that industry in such a manner as its produce may be of the greatest value, he intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part of his intention."
Smith's main thesis, depending as it does on this and so many other psychological assumptions that no longer apply (if they ever did) can be judged irrelevant in an era when the support of domestic industry is widely regarded as the quaint province of paleoconservatives and the pathetic remnants of American unions (and their liberal throwback supporters).
On the other hand, Smith did assert that the interests of businesses are often at odds with those of the public; also warning against political systems dominated by business, both of which observations seem quite applicable today.