Soaring US debt may start to overwhelm America’s ‘exorbitant privilege’

• Moody's added to the growing list of US debt warnings and appeared to inch closer to a downgrade in a recent report that sounded the alarm on the deteriorating fiscal situation. The ratings agency said America's AAA grade increasingly relies on "the unique and central roles of the dollar and Treasury bond market in global finance," but soaring debt and deficits are offsetting those advantages.

America has long enjoyed the "exorbitant privilege" of the dollar's status as the global reserve currency, but worsening debt and deficits could soon outweigh that immense advantage.

On Tuesday, Moody's added to the growing list of US debt warnings in a report that sounded the alarm on the deteriorating fiscal situation.

The ratings agency said America's triple-A grade increasingly relies on "extraordinary economic strength and the unique and central roles of the dollar and Treasury bond market in global finance."

Moody's noted higher interest rates have made debt less affordable. That's partly a result of rate hikes from the Federal Reserve to rein in inflation as well as massive deficits under President Joe Biden.

But it also said President Donald Trump's policies could worsen the situation and neutralize America's financial advantages.

"The potential negative credit impact of sustained high tariffs, unfunded tax cuts and significant tail risks to the economy have diminished prospects that these formidable strengths will continue to offset widening fiscal deficits and declining debt affordability," the report said.

In fact, the Congressional Budget Office said last Friday that if tax cuts from Trump's first term are extended permanently, debt held by the public would reach 214% of GDP in 2054.

And if borrowing costs face more upward pressure amid the deteriorating fiscal conditions, amounting to an additional 1 percentage point, debt would hit 204% of GDP in 2047 and exceed 250% in 2054.

Moody's is the last of the major rating agencies that still gives US debt a top mark. Fitch cut the US by one notch in 2023, citing fiscal deterioration and repeated debt-ceiling brinksmanship. That followed a similar downgrade from Standard & Poor's in 2011 after an earlier debt-ceiling crisis.

In November 2023, Moody's lowered its outlook on US debt to negative, which is often a precursor to an eventual downgrade of the credit rating.

The latest report showed no sign of improvement. By 2035, Moody's estimated the US will spend 30% of its revenue on paying interest on its debt, up from 9% in 2021 when borrowing costs were still low. Meanwhile, debt will rise to around 130% of GDP by 2035 from nearly 100% in 2025.

Even under the rosiest scenario, "debt affordability remains materially weaker than for other Aaa-rated and highly rated sovereigns," suggesting Moody's may be inching closer to a downgrade.

The White House didn't immediately respond to a request for comment on the Moody's report, but has previously said the Trump administration’s supply-side reforms, such as more energy production, deregulation and spending cuts, will spur growth and expand the tax base. That would also lower inflation, allowing the Federal Reserve to cut interest rates and ease borrowing costs.

JPMorgan chief economist Bruce Kasman told Fortune that America's outsized advantage remains intact, noting its rule-based system, enormous amount of liquidity, and strong economy.

"I think we still maintain what's often described as 'exorbitant privilege' in terms of the willingness of foreigners told US assets," he said in an interview a day before the Moody's report.

But he added there are some risks to that, especially if the US fails to bring its unsustainable deficits under control, obscures economic data, or forces bondholders to accept longer maturities, alluding to the notional "Mar-a-Lago accord."

If America's privileged positions starts to erode and demand for US assets drops, Kasman sees a shift playing out over time via sustained higher costs of financing debt, rather than in a sudden crisis.

"Oftentimes these are things which reflect slow material shifts and underlying trends. I think that's the probably the bigger risk we're facing here," he explained, adding that it could translate to an increase of 50 to 100 basis points in borrowing costs.

This story was originally featured on Fortune.com