Belgium is small and generates a disproportionate amount of urgent traffic, for three unrelated reasons. The first is Antwerp: a very large share of the world's diamonds passes through a few streets there, and stones move by named custodian rather than by parcel network for reasons that need no explanation. The value density is extreme, the items are tiny, and the handover has to be documented.
The second is biotechnology. The Flemish life science cluster around Ghent and Leuven and the biopharmaceutical manufacturing in Wallonia work directly with American sponsors, and the traffic is the usual life science profile: investigational product, trial samples and reference standards, with a stability window rather than a delivery date.
The third is Brussels itself. The European institutions, the regulatory bodies and the legal community around them generate a constant flow of filings, originals and executed instruments where the deadline is a submission hour and a scan does not satisfy the requirement.


