Clint Watts’s engaging new book, Messing With the Enemy: Surviving in a Social Media World of Hackers, Terrorists, Russians, and Fake News, is about forms of engagement. Watts’s experiences as an Army officer and FBI agent are important to his background. He begins the book with his interactions, through his blog and Twitter feed, with an American-born member of al-Shabaab, Omar Hammami, and then shares his observations about the Syrian Electronic Army’s insistent Twitter presence before examining Russian influence operations in the 2016 election.

Watts writes about how social media is exploited to widen divisions between people, organizations, and states. Hammami’s fractious, ultimately fatal, relationship with al-Shabaab gave Watts insight into the fractures inside al-Qaeda, which foretells how ISIS’s social media-driven caliphate eclipsed al-Qaeda’s internet-driven influence. This early illustration illuminates how social media is a self-closed place as well as an engine to drive change in the world, dual realities made possible by its very nature, but that can be used by actors to their own ends.

Messing With the Enemy owes something to the raft of post-9-11 books on cyberspace, cyberwarfare, and counterterrorism. It’s not, however, an in-depth look at government programs in the manner of Shane Harris on Total Information Awareness in The Watchers, nor is it about America’s development and deployment of cyber capabilities.

Social media’s distinctive capability and vulnerability, Watts makes us see, is sociality itself. A piece of information sits well with us not only because of its nature, but because it comes from someone we’ve let in our circle of trust; it is rejected because it comes from someone outside our circle of trust.

Social media vastly complicates this dynamic because the person who posted may not be who their profile and picture declare. Watts’s vivid descriptions of the profile pictures and bios of accounts that make Americans think they are interacting with other Americans are among the liveliest parts of the book. @TEN_GOP, a now-deactivated twitter feed, was meant to look like it came from the Tennessee GOP even though it was controlled by a Russian troll farm called the Internet Research Agency. It was so plausible that well-known Americans with large followings on Twitter retweeted it.

What’s shared on social media, Watts makes clear, doesn’t stay on social media. The capacity to bring people together or nudge them to act in physical space is potent. His discussions of Jade Helm 15 and the Alaska Back to Russia petition on the WhiteHouse.gov website and Paul Manafort’s claim that a NATO airbase in Turkey had been attacked demonstrate the back and forth between what’s said online and what happens in the world we all share. In the case of Jade Helm, the power of social media caused a sitting governor to take action.

In fact, what happens on social media spills into the world, which then feeds back into social media. Part of the Russian disinformation campaign involves using contentious social issues to play different sides against each other. In some cases, groups on opposite sides were pushed to meet in the same place at the same time. The real-life confrontation that resulted was engineered in the virtual world so that it could feed back into that very same world. This looping doesn’t merely reproduce existing divisions, it deepens them.

The seeds of this book about media were planted in different media including Watt’s Twitter feed @selectedwisdom, a blog of the same name, articles in The Daily Beast and War on the Rocks, and the March 2017 appearance at the Senate Select Committee on Intelligence, especially his response to a question from Senator James Lankford (R-OK). The visceral immediacy of reading Twitter is blunted by reading a book about reading Twitter. On balance, this is probably good. The roominess of a book allows Watts to develop contexts for being on social media that are lost in the actual experience of being on social media.

Messing With the Enemy is about who we choose to amplify. Reviewing a book is, of course, its own form of amplification, a kind of retweet with comment. Messing With the Enemy is content well worth sharing.

Katherine Voyles lives, teaches, reads and writes in Seattle.