nouns - Choice of articles: the reduction/ a reduction /reduction

I am often confused about the use of articles before abstract nouns. Are the following three sentences all grammatically correct? If so, what differences are there, if any, in their meaning or nuance?

(1) Obama chose the middle ground, ordering the reduction of U.S. troops to 50,000 by August 2010.

(2) Obama chose the middle ground, ordering a reduction of U.S. troops to 50,000 by August 2010.

(3) Obama chose the middle ground, ordering reduction of U.S. troops to 50,000 by August 2010.

Please assume that this reduction of troops has not been mentioned before this sentence, thus "the reduction" in (1) does not refer to something already mentioned.