No, I haven't read the book. I'm familiar with the Mena Airport operation, which was set up by the CIA after the Democrats in congress denied any funding for the Contras in Nicaragua.
Bush senior (as Reagan's VP and former CIA director) and Bill Clinton (as Governor of Arkansas) worked together on this project. My sense of the business, however, is that clinton was in it for the drug money and Bush was in it as a matter of patriotism, to defeat the Sandinistas. Iran-Contra, of course, was demonized by the Democrats and the media. But it was preferable to letting Communists take over Latin America, as they threatened to do.
It's not just "Iran-Contra" but the fact that there was drug smuggling going on and they were behind it and helping to grease the wheels to make it happen.