The Iraq War in 2003 (U.S. vs. Saddam regime) and the U.S.-Iran conflict in 2026 (U.S./Israel vs. Iran). Let's clarify the reasons separately.

1. 2003 Iraq War (U.S. vs. Saddam Regime)

Immediate pretext:

• Iraq possessed weapons of mass destruction (biological/nuclear weapons)

• Saddam regime supported terrorism and had links to "9/11"
(Post-war confirmation: no WMD found, no definitive connection)

Deeper underlying reasons:

1. Remove anti-American regimes and control the Middle East
Saddam was anti-American for a long time. The U.S. aimed to overthrow him, establish a pro-American government, and control Middle Eastern geopolitics and oil.

2. Oil and dollar hegemony
Iraq has huge oil reserves. The U.S. wanted to control oil prices and maintain the petrodollar settlement system.

3. Counterterrorism and domestic politics
Using the post-9/11 anti-terror atmosphere to divert domestic conflicts and strengthen the Republican Party’s rule.

2. The 2026 U.S.-Iran conflict (U.S. + Israel vs. Iran)

Immediate trigger (2026.2.28):

• U.S. and Israel claim Iran’s uranium enrichment is close to weapons-grade (90%), crossing the "red line"

• Nuclear negotiations break down, Israel conducts airstrikes on Iran’s nuclear facilities, and the U.S. intervenes fully

Deep root causes:

1. Nuclear issue: a security deadlock

◦ Iran: insists on peaceful nuclear sovereignty, advancing high-enrichment levels

◦ U.S. and Israel: see Iran’s nuclear program as a survival threat, will not allow Iran to acquire nuclear weapons

2. Middle East hegemony struggle

◦ Iran: forms a "Shia resistance axis" through Hezbollah, Houthi, Iraqi militias, challenging U.S.-led order

◦ U.S.: aims to weaken Iran, strengthen Gulf allies, and control the Strait of Hormuz (the global oil choke point)

3. Petrodollar hegemony
Iran promotes de-dollarization of oil trade (settling in RMB, euro), directly undermining the dollar’s foundation

4. Israel’s security anxiety
Israel views Iran as its top enemy, lobbying for military strikes to eliminate missile and nuclear threats

5. U.S. domestic politics
The Trump administration used war to divert scandal pressures, boost election prospects, and cater to pro-Israel and military-industrial groups

6. Historical grievances (since 1979)
Anti-American sentiment after the Islamic Revolution, hostage crisis, long-term sanctions, ideological confrontation, no trust foundation

Summary in one sentence:

• 2003 Iraq War: U.S. used anti-terrorism to remove anti-American regimes, seize oil, and control the Middle East

• 2026 U.S.-Iran conflict: nuclear red line + Middle East hegemony + petrodollar dominance + Israeli push + U.S. domestic politics all erupting together