As the 20th anniversary of the Iraq war passes, many are looking back at what is now considered by most to be one of the greatest foreign policy mistakes in American history. After the 2003 invasion, the U.S. would suffer over 4,000 casualties and many more Iraqi civilians killed before America’s combat mission finally ended in 2011.

Over seven years of war. Today, it is worth remembering those who said it would be a short war.

[Fair enough. But also in fairness, the main war aim was achieved relatively shortly — the destruction of Saddam Hussein’s reign almost immediately, and even his capture nine months later. It was the consequences of that attempt at regime change that shifted our goals to nation-building, and which committed us to a generation of cleaning up after regime change. That was true in Afghanistan as well, with much less success, and it’s also true in Libya, where regime change on the cheap created the failed state that has existed for more than a decade. The real lesson here is that even arguably justified regime change — and let’s not forget that Saddam once sent an assassin squad to target Geoge H. W. Bush after he left office — creates all sorts of long-range consequences and entanglements. — Ed]