A privateer was recognized by France, England, Spain and other countries as a legitimate war tool as opposed to a pirate who does not have the backing of a national government. What countries recognized privateers as a legitimate tool of war as opposed to just a pirate. Being a Privateer did have an advantage over being a pirate .
Are you sure about Spain?
I thought so, but it may not be so.
Spain used privateers. Two more countries you didn’t list were the United States, and during the Civil War, the Confederacy.
I read a book on the Confederacy privateers, which is why i thought of this distinction in the first place. They used the special rules for privateers to avoid being captured in port.
Given that the Dutch were a major naval power in the 17th century and hated the Spanish, they probably some sort of privateering effort.
Would modern day Somalia count?
Famously, you also had the Marathi privateer Kanhoji Angria and the Turkish privateer Murat Reis. Likewise, even though we call the Barbary Pirates pirates, they were in effect privateers, working first for the Ottoman Empire and then for their quasi-independent city states.
I think the general rule is that every country recognizes their own privateers, and considers everyone else’s to be dirty despicable pirates.
No, as far as I know there isn’t any evidence that the Somali government is supporting the pirates. The problem in Somalia is that there isn’t any governmental authority with the ability to crack down on pirates (or enforce law and order in general).
early 19th century America, including both United States as such and the Confederacy for as long as it existed.
E.g. privateers were basically the only sort of American naval activity against the British during the war of 1812.
ETA: Captain Amazing beat me to it.
ETA2: see here for mention of Dutch privateers Piracy and Privateering in the Golden Age Netherlands | The English Historical Review | Oxford Academic
No. That’s the point of being a Privateer, if your captured by an enemy, your taken prisoner of war, as opposed to being hanged as was done to pirates.
Not generally. The countries being preyed on by privateers generally didn’t appreciate the legal distinction, and generally if they were captured by the enemy, they didn’t have a long lifespan afterwards.
What? How about USS Constitution defeats HMS Guerriere. USS United States defeats HMS Macedonian. USS Hornet sinks HMS Peacock. HMS Shannon defeats USS Chesapeake. There were plenty of battles involving US Navy ships in the war of 1812. In general, privateers don’t fight enemy warships (by choice anyway) - they raid enemy merchant shipping to make money.
One had a license from one’s government to attack enemy shipping. Foreign governments recognized the enemy country’s license, at least according to Patrick O’Brien. 
This reminds me of the West Wing episode where Mrs. Bartlet is on fire because her Daughters of the American Revolution membership linked to an ancestor who was a ‘privateer’.
I believe the term “Letter of Marque” was preferred.
According to
The United States could, in theory, authorize privateers today, since the US never signed a treaty renouncing privateering and the US Constitution specifically authorizes Congress to issue Letters of Marque and Reprisal.
Tell that to Jean Fleury, hanged by the Spanish in 1527, Bernard Speirdyke, hanged by the Spanish in 1670, the aptly named William Death, who was shot by the French in 1756 after his ship was captured by the French, and Abraham Lincoln, who issued a proclamation at the beginning of the Civil War that all Confederate commerce raiders would be charged with piracy and hanged, only to back down when Jefferson Davis threatened to hang any captured American sailors.
If you were lucky, a letter of marque would at least keep you from being executed by your own side. If you were Captain Kidd. . .
One could as easily cite slaughters of prisoners of war, from Napoleon at Jaffa, to Fort Pillow, to Malmedy. That wouldn’t demonstrate that killing POW’s was standard and accepted practice among modern Western nations.
Generalizing about captured privateers is difficult. Spain, it’s true, seldom gave quarter. For many centuries Spain had the most lucrative commerce, and a weak navy to protect it, and had more reason then most countries to hate privateers.
Other countries varied over time. In the Civil War, the American government did threaten to execute Confederate privateers, but it wasn’t because the US rejected letters of marque on principle, it was because it didn’t recognize the Confederacy. Lincoln did back down, fearing retaliation, but even if he hadn’t he might have had trouble sustaining piracy convictions in the Supreme Court.
The British had the same issue with Americans during the Revolutionary War. They threatened to hang, but never did, but they didn’t grant POW status either, leaving the prisoners in a Guantanamo-like legal limbo. Considering conditions in British prison camps, hanging might have been an act of mercy. During the War of 1812, captured Americans faced the added danger of impressment.
But in general, of the thousands of privateers captured in the Seven Years War, Revolutionary War, and Napoleonic Wars, relatively few ended up hanging from a yardarm.