While conflict can decimate individual national markets, a globally diversified portfolio remains the most resilient defense against geopolitical uncertainty.
The Fragility of National Markets
War is, above all else, a human tragedy. Yet for centuries, conflict and financial markets have been inextricably intertwined. When we examine the historical record, the most striking lesson is the sheer fragility of individual nations when they are on the losing side of a major conflict or internal revolution. In the most extreme cases, such as the Russian Revolution of 1917 and the conclusion of the Chinese Civil War in 1949, domestic and foreign investors saw their assets effectively expropriated. The result was a total loss of capital.
The Russian example is particularly haunting for the modern investor. From 1865 to 1917, the St. Petersburg Stock Exchange actually outperformed the New York Stock Exchange, yielding returns nearly twice as high. This period of prosperity ended abruptly, serving as a stark reminder that past performance is no shield against systemic political collapse. Similarly, during World War II, German stocks lost over 90% of their real value, while Japanese stocks plummeted by nearly 99%. These are not mere market corrections; they are the "left tail" events that can erase a lifetime of wealth.
The Failure of Historical Analogies
Investors often fall into the trap of trying to learn from the previous war to predict the next one. As historian Niall Ferguson notes, there is no simple recurrent pattern in how markets respond to conflict. In the late 1930s, investors tried to apply the lessons of World War I to their portfolios, only to find they were making entirely new mistakes. The variables—military technology, government regulation, and global trade links—shift so significantly between eras that historical analogies often provide a false sense of security.
During World War I, the global equity index lost about 31% in real terms. However, those who tried to avoid similar pain by exiting the market before World War II missed out on significant gains; US stocks delivered 22% and UK stocks 34% in cumulative real returns during that conflict. Financial markets are inherently random and difficult to learn from in real-time. Attempting to make tactical asset allocation decisions based on the outbreak of war is usually a losing game because the discount rates and expected cash flows are recalibrated by the market faster than an individual can react.
The Illusion of the Bond Safe Haven
Conventional wisdom suggests that bonds act as a safe harbor when the world is in turmoil. History suggests otherwise. Over the last 120 years, several countries have experienced negative real bond returns for the entire period, largely due to wars and their inflationary aftermaths. German bonds, for instance, lost all value during the hyperinflation of the early 1920s. Even the victors were not immune to long-term bond erosion.
Following the onset of World War II in 1940, US long-term government bonds lost 67% of their real value and did not fully recover in real terms until 1991. UK bonds suffered a similar fate, dropping 74% in real terms starting in 1946 and taking until 1993 to recover. This does not mean bonds have no place in a portfolio—they remain generally less volatile than stocks—but it highlights the necessity of global bond diversification. Relying on a single nation's debt, even a superpower's, introduces a level of concentration risk that war can cruelly expose.
The Resiliency of the Global Whole
While the destruction of individual markets is terrifying, the story of the globally diversified investor is one of remarkable resilience. Despite two world wars, the Cold War, and numerous regional conflicts, global stocks have returned a real 5.2% annually over the last 121 years. Interestingly, the most severe drawdowns for global investors have not occurred during wartime, but during peacetime economic shocks. The 54% drop during the 1929 crash and the 41% decline during the 2008 financial crisis were both more severe than the global market's experience in either World War.
The data suggests a simple, if uncomfortable, truth: if an investor cannot handle the volatility associated with war, they cannot handle the volatility of the stock market in general. Diversification across countries, asset classes, and risk premiums—such as small-cap and value stocks—is the only proven method to dampen this volatility. For example, during World War II, US small-cap value stocks outperformed the broader market by 12% annually. By holding the whole world, the investor ensures that the total loss of one market is offset by the survival and eventual recovery of others.
Navigating Uncertainty
In the end, we must distinguish between risk, which can be quantified with probabilities, and uncertainty, which cannot. War falls squarely into the realm of uncertainty. As John Maynard Keynes observed, when we face a future about which we know nothing, the most rational path is to rely on the collective judgment of the world as expressed in market prices. We conform to the average because our individual judgment of the future is effectively worthless.
The longer the world goes without a major conflict, the harder it becomes for investors to imagine one. This complacency makes the eventual disruption feel more painful. The best defense is not a clever exit strategy or a bet on a specific outcome, but a robust, low-cost, globally diversified portfolio. By accepting that bad times are an inevitable part of the investment horizon, and by planning for them through broad exposure, an investor can survive the shocks of history and participate in the long-term growth of the global economy.