The pervasiveness of slavery

I've been reading Wikipedia's articles on slavery and piracy.  This started with wishing to know more about the Barbary pirates.  

What strikes me is how normal it was up to only a few centuries ago to live knowing that at any moment some group of armed men could come by, loot and destroy your community, slaughter most of the people you know and take the few survivors as slaves.  Having a strong army and lots of reliable allies was good for one's survival and prosperity.

Many of us in the West have forgotten this.  It's become normal here, now, to live on the coast or on the plains or anywhere else in our countries and not have to consider that some group will attack my community to rape, plunder, murder, enslave.  It's just not done here anymore.  And I fear that many of us have forgotten why it's not done here anymore.

WIkipedia's History of Slavery

A quote from Wikipedia's Barbary Pirates article:

In 1785 two ships (the Maria of Boston and the Dauphin of Philadelphia) were seized, the ships and cargo were sold and the crews were enslaved and held for ransom.^[13]

In 1786, Thomas Jefferson, then the ambassador to France, and John Adams, ambassador to Britain, met in London with Sidi Haji Abdul Rahman Adja, a visiting ambassador from Tripoli. The Americans asked Adja why his government was hostile to American ships, even though there had been no provocation. They reported to the Continental Congress that the ambassador had told them “it was written in their Koran, that all nations which had not acknowledged the Prophet were sinners, whom it was the right and duty of the faithful to plunder and enslave,” but he also told them that for what they considered outrageous sums of money they could make peace.^[14]