Decisions are made on the basis of incomplete information, as must be everywhere in the real world. Beyond that, everything is different. Currencies are not the same and they fluctuate, sometimes wildly. Governments come and go, sometimes quickly and without warning. Commercial laws can be confusing.
Dispute resolution is bound to be costly.
Business practices and standards vary widely. Foreign buyers have been known to default on the terms of a deal, Canadian suppliers too. And ships sometimes sink. Professionals in the business of assessing these risks are just that, professionals. They have a wealth of experience, an array of real time information at their fingertips, a crowded Rolodex of contacts.