I agree, but after being burned so many times by Duolingo for leaving it off in translating these one-word abstract phrases, I'm in the habit of putting it in anyway. In this way, Duolingo is kind of penalizing people for what would otherwise be a good translation practice by recognizing when the article is unnecessary and removing it for a more natural translation.
De acuerdo, en este caso. Spanish uses the definite article more than does English. But not all the time.
For examples, "Quiero proteccion." (I want protection.) "Quiero la protección que ofrece". (I want THE protection that it offers.)
Some general rules"
1) If the English has an definite article, the Spanish should.
2) In Spanish, if a noun is used as the subject, use a definite article 3) If a noun used as object is modified by an adjective or an adjective phrase, use an article.
4) Use an article after the verb "gustar"
"I like the grapes my brother grows." ("Me gustan las uvas que mi hermano crece.")
There are other rules, as well.
Thanks to rspreng for these.