The killing of Charlie Kirk last week was shocking, though perhaps not surprising. America has a long history of political violence, and Kirk’s death is only the most recent addition to a grim list. The assassinations of Lincoln, John F. Kennedy, and Robert Kennedy; the shooting of Ronald Reagan; the more recent attack on Donald Trump; the attempt on George Wallace; and the shooting of Congressman Steve Scalise at a baseball practice all sit alongside the January 6th insurrection and the plot to kidnap Michigan Governor Gretchen Whitmer. Violence has touched both left and right, and it has become something more than a series of isolated tragedies. It has become a recurring feature of American politics.  

The diagram shows two interlocking self-reinforcing cycles. On the left is the fast cycle, where events escalate in a matter of hours or days. Social media platforms amplify divisive rhetoric, which fuels hate and anger. That emotional energy spills into political violence, and each act of violence feeds straight back into anger and more polarizing rhetoric. At the same time, anger leads to divisive rhetoric and that rhetoric drives engagement on social media platforms.  

On the right is the longer cycle, which unfolds over months and years. Here, social media platforms and divisive rhetoric contribute to information fragmentation (everybody has their own curated version of the news). Information fragmentation increases political polarization and gridlock which in turn reduce the perceived responsiveness and effectiveness of government and so to declining trust in government. That loss of institutional legitimacy creates reliance on guns in the absence of trusted protections, especially in a society where the Second Amendment is central to political culture. Greater access and reliance on firearms, in turn, make political violence more lethal and more frequent, further deepening the erosion of trust.

The fast cycle of outrage and retaliation injects energy into the longer cycle of institutional decay and gun reliance, while the slower process of erosion makes each flare-up of violence more dangerous. Together, they form a feedback system with no internal dampening: anger leads to violence, violence to distrust, distrust to more reliance on guns, and guns to more violence. 

In my lifetime I can recall only two high-profile killings of British politicians: Jo Cox in 2016 and David Amess in 2021. Before that, you would have to reach back into the Troubles in Northern Ireland, which was closer to religiously motivated civil conflict than to the ordinary functioning of parliamentary politics. Both countries are increasingly politically polarized, both are exposed to the same social media platforms that amplify outrage, and both have populist figures who thrive on divisive rhetoric. Yet in the United States violence is woven into the fabric of politics, while in Britain it remains an exception.  While there are several way in which the United States and the United Kingdom differ (the length of their histories and traditions, their experience with immigration, their constitutions - one written, one unwritten) one that seems particularly salient relates to the Second Amendment.  

In the United States, the Second Amendment has created not only access to guns but also a sense of security and the perception that they are the "last line of defense", a last resort when government fails.  As trust in government has declined, the logic of arming for self-protection has grown. Geography reinforces this dynamic: in remote rural communities, law enforcement cannot always be relied on to respond quickly, while in large cities police forces are often underfunded, overstretched, or poorly trained. In both contexts, cities and remote rural communities, the perception is that the state cannot protect you, so you must protect yourself.  However there is an unintended side-effect; as more people own guns, the likelihood that political disputes escalate into political killing rises. 

The United Kingdom differs not because its social media platforms are less corrosive but because there are important cultural and structural differences of which there are many. Britain's democratic  institutions are underpinned by longer democratic traditions and norms. Its “unwritten constitution” rests on conventions that still command legitimacy; but perhaps most importantly guns are not seen as an essential backstop for settling disputes. And without either the provisions of the Second Amendment nor strong public support for the liberalization of gun control, firearms are harder to obtain. While political extremism is arguably as common in both countries, with less access to guns, the likelihood of a political fanatic actually shooting a political figure is far lower. 

In America, violence begets anger, anger feeds divisive rhetoric, rhetoric spreads through platforms, and trust erodes further. Guns are a significant contributor to this cycle, ensuring that when anger erupts, the consequences are more often fatal. The result is a self-reinforcing system where every act of violence makes the next more likely. That is why the killing of Charlie Kirk feels both shocking and inevitable. Without something fundamentally changing this cycle will continue to accelerate, not slow down.  But change requires a sober collective approach in which both sides coming together to solve the problem and this cycle, like all cycles of escalating violence, pushes us further apart rather than bringing us together. 

After every shocking act of political violence in America, we hear the now all-too-familiar chorus: “This is not who we are.” But while it may not be who we are as individuals, it is, sadly, who collectively we have become as a society. We have allowed a system to evolve in which violence is endemic, and we have failed to take meaningful action to change it. If we fail again, as we have so often in the past, then we must also be honest enough to acknowledge the consequences.