Are there conditions that can be satisfied to justify a pre-emptive military strike?

Ten years ago this week the U.S. invaded Iraq under the pretext that the country possessed weapons of mass destruction. The pretext turned out not to be true, but was used to justify a pre-emptive attack. Today's Question: Are there conditions that can be satisfied to justify a pre-emptive military strike?

MPR News is Reader Funded

Before you keep reading, take a moment to donate to MPR News. Your financial support ensures that factual and trusted news and context remain accessible to all.