Every time a new conflict makes headlines, the same question takes over financial media: “What does this mean for the market?” It happened after Russia invaded Ukraine. It happened when Hamas attacked Israel. It happened again in early 2026 when tensions between the US and Iran started escalating into something nobody wanted to call a war but nobody could call peace either.

And every time, the takes fly. “Markets hate uncertainty.” “Buy defense stocks.” “Sell everything and wait.” Most of these takes are useless — not because they’re always wrong, but because they ignore the one thing that actually helps: looking at what happened before, in specific detail, with real numbers.

So that’s what we’re going to do. I’ve pulled data from every major military conflict since World War II and laid it out plainly. Some of it will surprise you. Some of it won’t. All of it is more useful than the panic-driven commentary you’ll find on social media the day a missile is launched.

World War II: The Market That Rallied Through the Worst of It

This is the one that catches people off guard.

You’d think the deadliest conflict in human history would’ve destroyed stock prices. And for a while, it did. The US market fell sharply through 1940 and into the spring of 1942. The S&P 500 dropped 12.3% in the three months before the war’s start. After Pearl Harbor in December 1941, stocks dipped about 2.9% in the immediate aftermath.

But here’s the part nobody expects: the market bottomed in May 1942 and then rallied — hard — for the rest of the war. The Dow Jones gained roughly 50% from 1939 to 1945, working out to about 7% annualized. US small-cap stocks surged over 30% during the same period.

What drove it? Wartime mobilization. The US government poured money into manufacturing, employment hit record levels, and corporate earnings — particularly in industrial sectors — boomed. The uncertainty was enormous, but the economic engine underneath was running flat out.

The lesson here isn’t “wars are good for stocks.” It’s that market performance during a conflict depends far more on the underlying economic conditions than on the conflict itself. The US was ramping up production on a massive scale. That mattered more to stock prices than the actual fighting.

Korea: A Quick Panic, Then Business as Usual

When North Korea invaded South Korea in June 1950, the Dow dropped 5% in a single day. The S&P 500 lost 5.38% right off the bat. Classic fear response.

Then it recovered. And it kept climbing.

By the time the war ended in 1953, the S&P 500 was nearly 30% higher than the day the invasion started. The annualized return during the Korean War was 18.7%. The S&P 500 actually gained 31.7% in 1950, the very year the war began.

This is one of the clearest examples of a pattern that shows up again and again: the initial shock is real, the recovery is often faster than anyone expects, and the medium-term trajectory is driven by economics, not geopolitics. The post-war US economy was expanding rapidly. Consumer demand was surging. The Korean conflict, despite everything, wasn’t enough to derail that momentum.

Vietnam: A Decade of War, a Decade of Mediocre Returns

Vietnam is the interesting counterexample.

When American troops landed in 1965, the Dow closed that year up 10%. By the time the conflict ended in 1973, the market’s total return was about 43%, which sounds decent until you annualize it to roughly 5–6%. That’s below the long-term historical average, and it lagged behind what investors could have earned in most other periods.

Vietnam is the war that actually weighed on markets — not because of the fighting itself, but because of what it did to the economy. The cost of the war contributed to rising inflation, balance of payments problems, and eventually the collapse of the Bretton Woods system. President Johnson’s “guns and butter” approach — fighting a war while expanding social programs — built inflationary pressure that took a decade to unwind.

The stock market during Vietnam didn’t crash. It just ground sideways while everything else got more expensive. For a long-term investor, the damage was real but subtle. You were making money on paper while losing purchasing power in your wallet.

The 1973 Oil Embargo: When War Hits the Energy Jugular

This one deserves its own section because it demonstrates the single biggest risk factor connecting wars to markets: energy.

The Yom Kippur War in October 1973 triggered the Arab oil embargo against countries supporting Israel. Oil prices quadrupled. The S&P 500 went on to lose nearly 50% from its January 1973 peak to its October 1974 trough. That’s not a typo. Half its value, gone.

This wasn’t just a war-related selloff. It was a structural economic shock. Quadrupled energy costs rippled through every part of the economy — transportation, manufacturing, consumer goods. Inflation spiked. The Fed raised rates aggressively. A deep recession followed.

The 1973 episode is the template for the worst-case scenario: a military conflict that directly disrupts global energy supplies. When that happens, markets don’t just dip and recover. They can enter prolonged, painful bear markets because the economic machinery itself is damaged.

Keep this in mind. It comes back later.

The Gulf War: Textbook Sell-the-Invasion, Buy-the-Resolution

August 1990. Iraq invades Kuwait. Oil prices spike. The S&P 500 falls roughly 16% between July and October as recession fears mount and the world waits to see what the US will do.

Then Operation Desert Storm launches in January 1991. Suddenly, the uncertainty is replaced by the one thing markets actually like: a clear outcome. The S&P 500 rallied and finished 1991 up about 26%. The Dow jumped immediately after the shooting started. Oil prices, which had doubled, dropped right back down.

This is the “sell the rumor, buy the news” pattern in its purest form. The anxiety before the conflict started was worse for stock prices than the actual war. Once investors could see what was happening and estimate how it would end, they bought aggressively.

The Gulf War is also the example people love to cite when arguing that wars don’t hurt stocks. It’s a fair example, but it comes with a major caveat: the war was short, decisive, and the oil supply disruption was quickly resolved. Not all conflicts end that cleanly.

September 11: The Shock That Proved Market Resilience

The NYSE and Nasdaq closed for four trading days after the attacks. When they reopened on September 17, 2001, the Dow dropped 684 points — a 7.1% decline, which was the largest single-day point drop in its history at that time. The S&P 500 fell about 5% that day, and over 14% in the first week of trading.

Devastating numbers. And completely temporary.

Within a month of the attacks, the S&P 500 had recovered all of its losses. In the six months that followed, the Dow gained 13% and the S&P 500 rose 5.6%. Since September 2001, the S&P 500 has surged over 310%.

Now, context matters. The 9/11 attacks occurred during the 2000–2002 bear market that was already underway because of the dot-com bust. Stocks were already cheap, sentiment was already terrible, and the Federal Reserve was already cutting rates. The recovery from the post-9/11 selloff was partly the market doing what beaten-down markets naturally do: bounce.

But the speed of the recovery sent a powerful signal. Even the worst terrorist attack in American history, one that shut the financial markets and fundamentally changed domestic and foreign policy, couldn’t keep stocks down for more than a few weeks.

Russia-Ukraine (2022): The Energy War That Reshaped European Markets

This is the first major land war in Europe since World War II, and the market reaction was a case study in how energy prices transmit conflict shock into financial markets.

The S&P 500 fell about 8% in the three months following Russia’s invasion of Ukraine in February 2022. Brent crude surged above $100 a barrel. European natural gas prices exploded as the continent scrambled to find alternatives to Russian supply. Moscow’s MOEX exchange crashed 33% in a single session, and the MSCI Russia index dropped 38%.

European markets took the worst of it. Countries with deep trade and ownership ties to Russia saw meaningful declines. The energy crisis contributed to a broader bear market in 2022 — not because of the military conflict per se, but because the economic consequences (energy prices, inflation, rate hikes) cascaded through global supply chains.

Stocks bottomed in October 2022 and started climbing. Russian oil, despite all the sanctions talk, mostly stayed on the market through indirect sales channels. Europe found alternative gas suppliers faster than expected. The war continued, but the acute economic shock faded.

The lesson from 2022: the war itself didn’t tank markets. The energy disruption did. Once the energy situation stabilized — not resolved, just stabilized — markets found their footing.

Israel-Hamas (2023): Limited Global Impact, High Regional Stress

The October 7, 2023, attack initially rattled global markets. Oil prices jumped. US futures dipped. Middle Eastern indices — particularly in the UAE, Israel, and Jordan — took immediate hits.

But the broader market reaction was surprisingly muted. The conflict, as horrific as it was, didn’t threaten global oil supply in any meaningful way. There was no oil embargo. No major shipping lane was permanently blocked. The Tel Aviv stock market actually rose 65% from the day of the attack through early 2026, as the Israeli economy proved more resilient than the initial panic suggested.

Defense stocks did well, predictably. US contractors with exposure to military demand saw positive returns correlated with the conflict’s intensity. But for the average investor holding a diversified global portfolio, the Israel-Hamas war registered as regional noise rather than a systemic event.

That doesn’t make it unimportant. It makes it a useful data point: not every conflict moves markets significantly. The ones that do tend to involve energy supply disruptions or major global economic powers.

Iran (2025–2026): The One We’re Living Through

I’d be leaving a hole in this article if I didn’t talk about what’s happening right now, even though it’s harder to analyze in real time.

The US-Iran tensions that escalated in late 2025 and into early 2026 have triggered a familiar pattern. Oil prices spiked on fears about the Strait of Hormuz — a chokepoint through which roughly 20–30% of the world’s oil passes. The S&P 500 dropped about 3.1% over a month. The dollar strengthened. Treasury yields rose. International stocks underperformed.

The market’s concern isn’t really about the military action itself. It’s about what happens to oil if the strait gets blocked even temporarily. Analysts have modeled scenarios where a two-week disruption could push oil above $150 a barrel. That kind of spike would accelerate inflation, force central banks to hold rates higher for longer, and potentially tip economies into recession.

As of mid-March 2026, that worst-case scenario hasn’t materialized. But the risk premium is priced in, and it’s keeping a ceiling on how far stocks can rally until the situation becomes clearer.

The Pattern: What 80 Years of Data Tell Us

After going through all of this, the pattern isn’t complicated. It’s just nuanced.

Conflict	S&P 500 Initial Reaction	Subsequent 12-Month Performance	Key Driver
World War II	-12.3% (3 months before)	+16.9% over full war period	Wartime production boom
Korean War	-5.4% initial drop	+18.7% annualized during conflict	Post-war economic expansion
Vietnam War	Mild	+5–6% annualized (below average)	Inflationary fiscal policy
1973 Oil Embargo	Severe	-50% peak to trough over 18 months	Energy supply shock
Gulf War	-16% (Jul–Oct 1990)	+26% in 1991	Quick resolution, oil recovery
9/11	-14% first week	Recovered within 1 month	Existing bear market, Fed cuts
Russia-Ukraine	-8% (3 months post)	Bottomed Oct 2022, rallied into 2023	Energy disruption, inflation
Israel-Hamas	Mild dip	Tel Aviv index +65% post-attack	No energy supply threat
US-Iran (2026)	-3.1% (1 month)	Still unfolding	Strait of Hormuz risk

A few things jump out:

1. The initial drop is almost always short-lived.
In 19 out of 20 major military events studied by RBC Wealth Management, the S&P 500 recovered to its pre-event level within an average of 28 days. The average maximum drawdown from geopolitical shocks is about 5–6%. Sharp? Sure. Permanent? Almost never.

2. Economic fundamentals win in the end.
The direction stocks go over the following year has far more to do with corporate earnings, interest rates, and monetary policy than with the conflict itself. Wars during expansions (WWII, Korea) saw strong markets. Wars during inflationary periods (Vietnam, 2022) saw weaker ones.

3. Energy is the transmission mechanism.
The conflicts that hit markets hardest are the ones that disrupt energy supply. The 1973 embargo and the 2022 Russia-Ukraine gas crisis are the standout examples. When oil or gas prices spike enough to change inflation and interest rate expectations, the damage can be severe and lasting.

4. Defense stocks are the obvious play — but not always the best one.
Yes, Lockheed Martin and Raytheon tend to rally when tensions rise. But the outperformance is often front-loaded and short-lived. Over longer periods, broader market returns typically outpace defense sector gains during conflicts.

5. Surprise attacks cause sharper drops than anticipated conflicts.
Pearl Harbor, 9/11, Russia’s invasion — surprise events trigger bigger immediate selloffs than slowly escalating tensions like the Gulf War buildup or the US-Iran situation unfolding now. But surprises also tend to see faster recoveries because the uncertainty resolves more quickly.

What This Means for Your Portfolio in 2026

If you’re reading this in March 2026 with the Iran situation still simmering, here’s what the historical record would suggest — keeping in mind that history rhymes but never repeats exactly.

Don’t sell into the panic. The data on this is overwhelming. Investors who sold during the initial shock of a geopolitical crisis were wrong the vast majority of the time. The average 12-month return after a geopolitical event is positive. Selling into a 5% dip and buying back 15% higher is not a strategy. It’s an expensive emotional reaction.

Watch oil, not the headlines. The single best predictor of whether a conflict will matter for your portfolio is what happens to energy prices. Crude oil above $100 starts to worry. Above $120 hurts. Above $150 restructures the economic outlook. Track Brent crude, natural gas futures, and shipping rates through the Strait of Hormuz. Those numbers tell you more than any pundit on television.

Understand the second-order effects. Here’s the chain that trips people up: oil spikes → inflation expectations rise → central banks tighten → the dollar strengthens → stocks fall. The direct fear-driven selloff from a war is usually small. The indirect damage from the economic chain reaction can be much larger. This is why the 1973 and 2022 episodes were so painful — not because of the wars, but because of what the energy shocks did to monetary policy.

Gold is a reasonable short-term hedge, not a magic shield. Gold tends to rally in the first days and weeks of a crisis. But if the crisis causes oil to spike and interest rates to rise, gold can actually fall in the medium term — exactly when you’d expect it to protect you. Keep your gold allocation steady. Don’t pile in after the headlines start.

Diversification actually works here. International stocks, bonds, commodities, and cash all behave differently during geopolitical events. A reasonably diversified portfolio experiences smaller drawdowns and faster recoveries than a concentrated equity position. This is one of the few situations where the textbook advice about diversification actually delivers visible results.

The Uncomfortable Truth

Markets have survived every war in modern history. That’s a factual statement backed by decades of data. And yet, it’s also a somewhat uncomfortable thing to write in an article, because wars aren’t an abstract concept. Real people suffer. Economies in conflict zones get destroyed even as stock markets elsewhere shrug it off.

The S&P 500 recovering in 28 days after a military event doesn’t mean the event was insignificant. It means the US stock market — a specific measuring instrument for the expected future earnings of large US corporations — has repeatedly demonstrated that most conflicts don’t permanently alter the economic fundamentals that drive corporate profits.

When conflicts do permanently alter those fundamentals — through energy disruptions, supply chain breakdowns, or inflationary spirals — it shows up in the numbers. The 1973 bear market and the 2022 downturn are proof of that.

The takeaway isn’t “don’t worry about wars.” It’s “worry about the right things.” Watch energy. Watch monetary policy. Watch corporate earnings revisions. Those are the channels through which conflict enters your portfolio, and those are the signals that distinguish a buyable dip from a genuine bear market.

Most of the time, the market figures it out faster than the headlines would suggest. But “most of the time” isn’t “all of the time,” and the exceptions — when energy gets disrupted at scale — are genuinely dangerous.

Know where the risks are. Size your positions so you can ride out the volatility. And resist the temptation to make portfolio decisions based on cable news coverage of events that, historically, tend to matter far less to your money than you’d think.

This article is for educational and informational purposes only. Nothing here constitutes financial advice, investment advice, or a recommendation to buy or sell any asset. Stock markets are volatile and past performance does not guarantee future results. Geopolitical events carry unpredictable risks. Always consult a qualified financial advisor before making investment decisions and only invest capital you can afford to lose.