Water scarcity in the American Southwest poses a significant threat to national security.

What's this about?

People disagree about whether too little water in the US Southwest threatens the whole country's safety.

Years of dry weather strain rivers, farms, cities, and the groups that share water.

What supporters say

• The Colorado River supports big cities, farms, power work, and nature across many states.
• Long water shortages force leaders to decide who gets less water and how key services keep working.
• Too little water can worsen money problems, social stress, and fights between groups.
• Hotter weather may make old river records less useful for guessing future water supplies.

What critics say

• The evidence does not show that water shortages cause an urgent national safety crisis right now.
• Studies cannot give an exact number for how much water loss could harm national safety.
• States, tribes, cities, farms, and water groups can still bargain over rules for sharing cuts.
• We are not sure how long future dry times will last or how well new plans will work.

The bottom line

Too little water in the Southwest creates a serious long-term stress for the country.

It does not prove that the nation faces an immediate safety emergency.