Those forces are the dark, behind-the-scenes, controlling financial, political, hereditarily powerful, elites that exercised much control of the US government in Kennedy's day, and complete control now (see Daniel Estulin's The Shadow Masters). In Dwight Eisenhower's parlance, they're the Military-Industrial Complex. In Occupy parlance, they're the One Percent. They can be seen at work in Dallek's book just from the recitation of historical events, but that Dallek doesn't identify them as a controlling force is, to me, his book's great failing and the reason for my three star rating.
To be sure, the book is about John F Kennedy and it relates the narrative of his life with great detail and engaging prose. We see his development from privileged youth to assuming the role of the "next in line son" upon the death of his older brother, his return from war as a wizened veteran, his political successes abetted by family money, his struggling as president to find the right way. And he accomplished all this with two glaring flaws--poor health and a sex addiction (though the two would seem to be mutually exclusive).
Kennedy's health problems were such that he went through periods on crutches and debilitated with gastric-based pain. Even so, he pushed himself to engage in athletics (because fitness and being physically active were family expectations) and used his father's political influence to get him a combat assignment in the Navy during World War II. In fact, one of this book's great revelations (maybe the biggest one) is just how bad JFK's health was throughout his life. But Kennedy kept his condition mostly secret so it wouldn't be used against him in politics or deny his desired military service. Much of what he accomplished in his life was done in the spite of physical ailments and sheer pain.
Dallek also made much of Kennedy's womanizing, as have others, though "womanizing" may be too polite a term for sex parties with prostitutes and seducing young interns. Even JFK seemed to acknowledge it as a compulsion that even he didn't understand. Still, this is not a revelation about Kennedy or even about other politicians in high office (Dallek says Lyndon Johnson had a room in the White House dedicated for such activities), but it does lend support to my belief that politicians are bought with sex as much as with campaign contributions.
Beyond these personal aspects of JFK's career, are the better known experiences that Dallek describes in detail bolstered with tremendous research and a thorough bibliography--the fiasco of the Bay of Pigs (cementing JFK's distrust of the CIA and the military), civil rights support (like using the National Guard to assist James Meridith's enrollment at Ole Miss), the Cuban missile crisis, and the US nascent involvement in Vietnam (his final opposition to which was, I believe, his undoing). All are described with interesting detail and intimations of Kennedy's personal take on each, pulled from his own writings or remembrances of people that were there.
So An Unfinished Life is a very enlightening tome about John F Kennedy as a man and a president. Historical events are described in detail, engaging the reader with JFK's viewpoint. But Dallek's angle on JFK and his times is very much "traditional" and worse, uncritical, of the political process and the greater perspective of elite greed and corruption that oppresses the current times. As such, it is difficult to read about politicians motivated by the "communist threat" when hindsight holds the United States governments equally responsible for the cold war's threat to world life and peace.
For example, there are numerous passages like this one from Chapter 5 that talks about Kennedy's beginning term as a Senator:
"...mounting national concern about the communist threat. With numerous labor walkouts over insufficient wage hikes...and growing fears of communist subversions and expansion..."
This passage is saying that the fear of communism gave the Republicans the Senate and House majorities in 1947. It is uncritical. What were these fears based on? Was communism really a threat to the United States or was the "threat" a cover for competition between totalitarian-imperialist regimes? Was the fear of communism created and egged on by the US elite for political advantage?
Such questions were considered traitorous 30 years ago, but today, we surely have a wider perspective to judge such things with more skepticism and less delusion.
Dallek describes Kennedy's aversion to making US military commitments to protecting the regime of South Vietnam from takeover by North Vietnam, but he does not question the source nor motive of the pressure to make that commitment. He seems to accept the notion of stopping communist aggression, with no mention of the "military-industrial complex" for whom unending war is a source of tremendous profits. When JFK opposed escalating the US involvement in Vietnam, I believe it sealed his doom. He was assassinated and his vice president, who in all else proceeded with Kennedy's agenda, increased the country's involvement in that conflict until it destroyed his presidency along with the fighting capability of the US army, and left a permanent scar on the national conscience (of the common people; not their rulers).
An Unfinished Life is a valuable book, but it should be read with the understanding that it tells John F Kennedy's story from a standpoint that believes in American exceptionalism and the purity of purpose of its elected officials. It believes in the "American Camelot."
Mr. Dallek tells a good story, he brings JFK and his times to life, but I believe the greater story lies between his lines.