Are investors foregoing the United States?

Tuesday 31 March 2026

In the modern global financial system, the United States has long occupied a singular position: the issuer of the world’s principal reserve currency and the sponsor of the deepest and most liquid sovereign bond market on earth. In moments of geopolitical crisis investors traditionally rush toward American government debt, buying United States Treasury securities and thereby lowering their yields. Yet the present conflict involving Iran has produced a more ambiguous pattern. While the United States dollar has strengthened in the immediate aftermath of the crisis, demand for longer-dated Treasury securities has at times been surprisingly weak. The divergence between currency strength and sovereign bond demand raises an important question for economists and policymakers alike: are investors beginning to reconsider the United States as the ultimate safe haven for global capital?

To understand the significance of this question one must first appreciate the traditional role of Treasury securities in global finance. The United States government bond market is the largest and most liquid sovereign debt market in the world. For decades investors facing uncertainty have bought Treasuries in vast quantities, accepting lower yields in exchange for the perceived safety of the American state and the institutional stability of its financial system. This behaviour was visible during the global financial crisis of 2008, the eurozone sovereign debt crisis and the early stages of the Covid-19 pandemic. In each case capital flowed rapidly into United States government debt.

The Iranian conflict however has unfolded against a markedly different macroeconomic background. Oil prices surged after the outbreak of hostilities, partly because roughly one fifth of the world’s oil supply passes through the Strait of Hormuz, whose closure or disruption has immediate effects on global energy markets. This spike in energy prices has raised fears of renewed inflation across the global economy. In such circumstances investors often hesitate to hold long-term fixed-income securities whose real returns may be eroded by rising prices.

The behaviour of Treasury yields during the crisis reflects this dynamic. Instead of falling in response to geopolitical risk, long-term yields have in some cases risen. The yield on ten-year United States Treasury securities climbed above four per cent shortly after the escalation of the conflict, indicating that investors demanded higher compensation to hold American government debt. Analysts have attributed this shift partly to inflation expectations driven by higher oil prices and partly to concerns about the future supply of United States debt as military spending rises. 

Evidence of weakening demand has also appeared in the Treasury auction market itself. Recent government bond auctions have been described as lacklustre, with investors requiring higher yields to purchase newly issued debt. Such episodes would once have been unusual during periods of international tension, when investors normally competed vigorously for the safety of American bonds.

Yet it would be misleading to conclude that investors are abandoning the United States altogether. Indeed the behaviour of the United States dollar during the conflict tells a different story. The currency has strengthened against most major peers, as global investors still perceive the United States as a relatively safe destination for capital. This apparent contradiction illustrates the complex nature of modern safe-haven flows. Capital can move into the United States without necessarily moving into long-term government bonds.

Several structural factors help explain this phenomenon. First, investors increasingly have alternative safe assets available to them. Gold prices surged during the early stages of the conflict, and currencies such as the Swiss franc and the Japanese yen have historically benefited from similar crises. Secondly, large institutional investors are increasingly holding cash, short-term securities or diversified portfolios rather than concentrating their holdings in long-dated sovereign debt. These shifts reflect a broader transformation in global financial markets in which liquidity, flexibility and inflation protection are increasingly prized.

Another structural factor is the growing scale of United States public debt itself. The United States federal government has run substantial fiscal deficits for many years, and wartime expenditures risk increasing those deficits further. As supply of government bonds rises, investors may demand higher yields to absorb the additional issuance. Economists have warned that expanded military spending linked to the Iranian conflict could widen the federal deficit and raise borrowing costs across the economy. 

More broadly, the present moment occurs within a longer trend sometimes described as gradual “de-dollarisation”. Although the dollar remains the dominant global reserve currency, its share of international reserves has declined modestly over recent decades as central banks diversify into other currencies and assets. The causes of this shift are complex. Some countries seek to reduce their exposure to United States sanctions policy, while others are simply pursuing more diversified reserve portfolios.

Nonetheless, the scale of this diversification should not be exaggerated. The United States continues to possess structural advantages that no rival financial centre currently matches. Its economy remains vast, its financial markets are deep and liquid and its legal institutions enjoy global credibility. Even investors sceptical of long-term Treasury bonds may still regard American assets in general as relatively secure compared with alternatives.

For the United States economy, the practical consequences of this evolving investor behaviour are potentially significant. The most immediate effect of weaker demand for Treasury bonds is upward pressure on interest rates. Higher government borrowing costs tend to transmit themselves throughout the financial system, raising mortgage rates, corporate borrowing costs and consumer credit interest rates. Such changes can slow economic growth over time by discouraging investment and consumption.

Higher yields also complicate fiscal policy. When the cost of servicing public debt rises, a larger portion of government revenue must be devoted to interest payments rather than public services or infrastructure. This dynamic can create a self-reinforcing cycle in which growing debt leads to higher interest payments, which in turn lead to further borrowing.

Yet the consequences are not entirely negative from Washington’s perspective. A stronger dollar, which has accompanied the crisis so far, reduces the cost of imports and reinforces the currency’s role in global trade and finance. Moreover if the United States economy continues to outperform many of its competitors, global capital may still flow into American equities, technology firms and private investments even if enthusiasm for long-term government bonds diminishes.

The ultimate significance of the present moment therefore lies less in an immediate flight from the United States than in the gradual erosion of a once unquestioned assumption. For decades the world’s investors treated United States government debt as the definitive refuge in times of crisis. The Iranian conflict suggests that this reflex is no longer automatic. Inflation fears, fiscal concerns and the availability of alternative assets are all shaping investor decisions in ways that complicate the traditional safe-haven narrative.

Whether this shift proves temporary or structural will depend largely upon the trajectory of the conflict and the broader fiscal policy of the United States. If oil prices stabilise and inflation recedes, demand for Treasuries may recover quickly. If, however, the war drags on and fiscal deficits expand further, investors may continue demanding higher yields to hold American debt.

The world has not yet ceased to regard the United States as a financial refuge. But the era in which that status was entirely uncontested may be quietly drawing to a close.