Mark Esper, who served as U.S. Secretary of Defense during Donald Trump's first term, said he does not see the war with Iran ending in the foreseeable future, a warning that adds to mounting unease in Washington over the conflict's strategic and economic spillovers. Speaking in the context of the widening confrontation, Esper framed the war not only as a military problem but as a long-duration geopolitical shock that could strengthen the position of a major U.S. rival if the fighting drags on.
War With No Exit
Esper's assessment reflects a broader fear among former officials and security analysts: that once a conflict with Iran becomes entrenched, it can be extraordinarily difficult to contain, much less conclude on favorable terms. A prolonged war would likely keep regional shipping lanes under pressure, sustain elevated security risks across the Middle East, and complicate any effort by the United States and its partners to restore predictability to energy markets.
His remarks come at a moment when investors, central bankers, and policymakers are already contending with a fragile global economic backdrop. Any extended conflict involving Iran carries implications well beyond military strategy. The Strait of Hormuz remains one of the world's most important energy chokepoints, and even the threat of disruption can feed into oil prices, freight costs, insurance premiums, and inflation expectations. For central banks, that creates an especially difficult policy environment: a war-driven supply shock can tighten financial conditions even as growth slows.
Strategic Costs Mount
Esper's warning that the conflict could benefit America's "greatest adversary" points to the wider geopolitical contest surrounding the war. A long conflict can drain U.S. attention, strain allied coordination, and create openings for rivals to present themselves as more stable partners to countries seeking energy, trade, and diplomatic flexibility. In practical terms, prolonged instability can also deepen fragmentation across global markets, encouraging more hedging, more bilateral deals, and less reliance on U.S.-led security guarantees.
For the United States, the risk is not only that the war becomes harder to end, but that the strategic burden expands over time. Military deployments, missile defense commitments, intelligence sharing, and maritime protection all become more expensive the longer hostilities persist. That can translate into higher fiscal costs at a time when Washington is already managing large deficits and political resistance to open-ended overseas commitments.
The economic consequences are equally significant. Oil markets often react first to Middle East conflict, but the effects can spread quickly into broader inflation dynamics. Higher energy prices can lift transportation and production costs globally, complicating the work of central banks that have spent the past two years trying to bring inflation under control without triggering a recession. A sustained war involving Iran would therefore be watched closely not just by defense planners, but by monetary authorities in the United States, Europe, and Asia.
Markets Watch Closely
The prospect of a long war also raises questions about market resilience. Equity investors tend to discount geopolitical shocks quickly when they appear temporary, but a conflict with no visible end point can alter risk appetite more durably. Safe-haven flows may strengthen the dollar and U.S. Treasuries in the short term, while energy-sensitive sectors, emerging markets, and import-dependent economies could face renewed pressure.
Esper's comments are especially notable because they come from a former defense chief who managed the Pentagon during a period of intense U.S.-Iran tension. His perspective carries weight in policy circles precisely because it blends operational experience with an understanding of how military conflict can reverberate through diplomacy and the global economy. The warning is not merely that the war is dangerous, but that its duration may be the most consequential variable of all.
For now, the absence of a clear off-ramp means the conflict remains a live risk for markets and policymakers alike. If Esper is right, the longer the war continues, the more likely it is to reshape the balance of power in ways that extend far beyond Iran's borders and into the core of the global economic system.