Harold Coyle is a writer of military fiction. He is also a retired officer in the United States Army, although when he started writing his books, he was on active duty.
His first book, Team Yankee, was a very straight ahead book about a tank company during a World War III scenario, with communists invading Germany. While the book is mostly full of technical armor talk, it still manages to fit in some character development.
His next book, Sword Point, introduced the character of Scott Dixon, who would be one of a number of reoccuring characters in his next five books. Sword Point described a war between the Soviet Union, the United States and Iran. It introduced much more personal complications, as well as sociopolical intricacies, then Team Yankee. It also had a larger scale view of the war then Team Yankee did, and described more types of sea and air warfare.
The books after Sword Point continued the trend of focusing more on political intrigue and character development then on straight ahead combat. A similiar progression can be seen in Tom Clancy's books, although Harold Coyle, being a much better writer, pulled it off.
Another interesting thing about Harold Coyle, although there is no doubt of his love for his country, he seems to take a dim view of military adventurism. In his books detailing conflicts in Columbia and Mexico, he criticizes the use of the military to make up for a "bankrupt foreign policy", or to prop up right wing regimes. All of this, and he works in lots of explosions.
After these books, he wrote a trilogy about the civil war, and then two more books about modern warfare. He is still currently writing.
Overall, I would say that Harold Coyle combines the guilty pleasure of reading Tom Clancy with some interesting and informative writing.