Trump is threatening to cut off trade with most of America's biggest trading partners, and the bigger danger is that those countries stop funding US debt.

• The threat covers Mexico, Canada, China, Japan, Germany, South Korea, India and Taiwan — about $300 billion in trade a month.
• For 80 years those countries took the dollars they earned selling to America and bought US government debt with them.
• Some are now pulling their gold out of the US and backing away from Treasuries.
• The real target is the Fed: tariffs are the pressure tool to force interest rates down.

Outlook: If foreign buyers keep stepping back from US debt, borrowing costs rise — the opposite of what the tariff pressure is meant to achieve.