Privateer
In 21st-century usage, a privateer is either an advocate or exponent of private enterprise rather than public (government) spending or an individual participating in motorsports, competing against corporate or 'works' teams.
In historical terms, a privateer was a pirate with papers, commissioned by his country's government to operate his privately owned armed vessel, to rob merchant vessels and pillage settlements belonging to rival countries.
The arrangement suited both parties. For the government, it added to the country's naval capabilities without requiring expenditure. It also offered rulers an opportunity to invest, possibly at arm's length, in their enemies' misfortunes. England's Elizabeth I may not have invested directly in Francis Drake's circumnavigation or given him a formal commission; her half-share of the Golden Hind's cargo exceeded the rest of her income for 1580.
For the participants, privateering provided opportunities for financial gain beyond what was possible in their peacetime activities. So did piracy, but the official commission usually protected privateers from accusations of illegality.
On the other hand, since privateering could be more lucrative than naval service, it could divert resources away from the 'official' service. There was no guarantee that privateers would return to their former employment when hostilities ended. In any case, there was no guarantee that someone carrying letters of marque would restrict his activities to vessels from the targeted country. This extracurricular raiding and pillaging was indistinguishable from piracy. At other times, outlaw pirates would operate with the tacit encouragement of a government but without the written legal authorisation given to privateers.
The line between privateer and pirate was blurred in historical settings where these practices were common. It lasted until modern systems of centralised military control caused the decline of privateering in the 19th century.
