  Trade networks, across which countries distribute their products, are crucial
components of the globalized world economy. Their structure is strongly
heterogeneous across products, given the different features of the countries
which buy and sell goods. By using a diversified pool of indicators from
network science and product complexity theory, we quantitatively confirm the
intuition that, overall, products with higher complexity -- i.e., with larger
technological content and number of components -- are traded through a more
centralized network -- i.e., with a small number of countries concentrating
most of the export flow. Since centralized networks are known to be more
vulnerable, we argue that the current composition of production and trading is
associated to high fragility at the level of the most complex -- thus strategic
-- products.
