U.S. debt suddenly draws weaker demand as $10 trillion must be rolled over this year amid Iran war. ‘The bond market remains undefeated’

President Donald Trump’s war on Iran is colliding with U.S. debt investors, who demonstrated less appetite for Treasury securities as hopes for a quick end to the conflict evaporate.

This past week, auctions for two-, five- and seven-year Treasury notes all drew weak demand, forcing yields to go higher than expected. That’s a stark contrast from last month, when a Treasury offering saw the highest demand ever in the history of 30-year auctions.

The short end of the yield curve...