The US war with Iran is escalating fast, with no exit in sight — bad news for troops, taxpayers, and the region.

• Trump threatened to bomb an Iranian bridge or power plant, including in Tehran, every time Iran attacks a ship in the Strait of Hormuz.
• The war has already cost $37 billion and killed 18 US service members, and the Pentagon wants $67 billion more.
• Each side keeps hitting back and climbing higher, and the US is running low on bunker-buster bombs, aviation fuel, and oil reserves.
• A ground invasion and even a small tactical nuclear strike on Iran's underground "Pickaxe Mountain" site are reportedly being weighed — moves that could pull in Russia, China, and North Korea.
• Iran quickly rebuilds bombed sites within weeks and has knocked out US bases and radar in the region, blunting America's ability to strike.

Outlook: More tit-for-tat escalation is expected, with a land war and wider global conflict seen as growing risks.