WASHINGTON — The clearest signs of the damage being inflicted on the American economy by the war on Iran are appearing far from the battlefield: in the U.S. Treasury market, in the price of oil, in the cost of borrowing and increasingly in the political mood of American voters.

The warning from Wall Street on Tuesday was stark. The yield on the U.S. government's 30-year Treasury bond climbed to 5.327 percent, its highest level since 2007, as investors confronted the prospect of prolonged war, higher oil prices and renewed inflationary pressure.

Reuters reported that the surge came even as expectations for additional Federal Reserve rate increases have weakened because of softer economic data.

That combination is particularly damaging for Washington. A weakening economic outlook would normally increase expectations for lower interest rates and falling bond yields.

Instead, the long end of the Treasury market is moving in the opposite direction. Investors are demanding higher returns to hold long-term U.S. government debt as the war and its energy consequences create fresh inflation risks.

The result is an increasingly uncomfortable economic picture for the United States: growth concerns on one side, inflation concerns on the other, and higher government borrowing costs in between.

Oil markets are sending an equally troubling signal.

Brent crude moved above $90 a barrel and remained around the $91 level on Tuesday as hopes for a diplomatic breakthrough between Washington and Tehran faded.

Reuters reported that oil prices rose for a third consecutive session as traders increasingly considered the possibility that disruption around the Strait of Hormuz could persist.

The significance for the American economy is immediate. Higher crude prices eventually feed into gasoline, transportation, manufacturing and household expenses. They can also push inflation higher at precisely the moment when policymakers would prefer to see price pressures ease.

The economic damage is therefore not confined to energy companies or financial markets. It reaches American households through fuel prices and businesses through transportation and production costs, while simultaneously raising the government's cost of borrowing.

The war has also created an extraordinary problem around the Strait of Hormuz, through which a substantial share of global energy shipments normally passes.

On Tuesday, Iran said the strait would remain closed until the United States fulfills conditions associated with an interim agreement, including the lifting of oil sanctions, the release of frozen Iranian assets, an end to the blockade of Iranian ports and an end to military operations.

President Donald Trump, meanwhile, said that no talks with Iran were taking place and none were scheduled. He also falsely claimed that the Strait of Hormuz was open.

The practical condition of the waterway is reflected in shipping traffic.

Commercial crossings have remained dramatically below normal levels, with Reuters reporting that traffic through Hormuz remained in the single digits even after a modest increase from the weekend.

For the American economy, that matters because a prolonged disruption does not have to eliminate global oil supplies entirely to cause economic damage. Uncertainty itself raises prices.

Tankers face greater security risks, shipping companies face higher insurance and operating costs, and energy traders must price the possibility that the disruption could last longer than expected.

That uncertainty was underscored Tuesday when a vessel was struck by an unknown projectile while transiting the Strait of Hormuz, according to the United Kingdom Maritime Trade Operations agency. Al Jazeera reported that the incident caused one casualty and damaged the ship's engine room.

Every such incident makes the restoration of normal commercial traffic more difficult.

For Washington, this creates a painful economic chain reaction. A war launched by the United States against Iran has now produced an energy problem that is being reflected in the price of oil; the oil shock is contributing to inflation concerns; inflation concerns are contributing to pressure on long-term bonds; and higher Treasury yields are increasing the cost of financing America's already enormous federal debt.

Reuters has previously documented how the war on Iran has shaken the U.S. government bond market, with the 30-year Treasury yield reaching around 5.2 percent during an earlier phase of the war as oil prices surged and investors worried about inflation. The latest move above 5.3 percent shows that the pressure has not disappeared.

The timing is especially difficult because the Federal Reserve is caught between competing pressures. Softer economic data have reduced expectations for further interest-rate increases, but an oil shock creates the possibility of renewed inflation.

Reuters reported Tuesday that markets were grappling with exactly this combination as bond yields rose despite weaker expectations for additional Fed tightening.

This is the kind of economic environment that policymakers would normally try to avoid: weaker economic momentum accompanied by higher prices.

The bond-market deterioration also has consequences for the federal government. When the yield demanded by investors on long-term Treasury securities rises, the government must pay more to borrow.

For a country carrying a massive federal debt burden, that is an increasingly serious concern.

The pressure is not limited to government finances. Higher long-term Treasury yields can influence mortgage rates and other borrowing costs across the economy. Businesses that depend on credit face a higher cost of capital, while households seeking mortgages or other long-term financing can face more expensive loans.

Thus, the consequences of the terrorist war on Iran are moving through the American economy in several directions simultaneously.

The oil market is under pressure. The Treasury market is under pressure. Inflation expectations are under pressure. And the political standing of the administration responsible for the war is under pressure.

A Reuters/Ipsos poll published Monday found Trump's approval rating had fallen to 33 percent, the lowest of his presidency. Sixty-four percent of respondents disapproved of his performance, while 80 percent said they believed the war on Iran would last a long time.

The poll also found that Democrats had gained an advantage over Republicans on the question of which party could better manage the economy, a notable development as the midterm elections approach.

The findings provide a political dimension to the economic figures appearing in markets.

The administration's argument that the conflict would be manageable is becoming harder to sustain as the war continues, oil prices rise and Americans become more concerned about its duration.

The Reuters/Ipsos survey indicates that the public is increasingly looking beyond the military aggression and toward its consequences at home.

The deterioration is particularly striking because economic performance is traditionally one of the most important factors shaping presidential approval.

A president can withstand political controversy when voters believe their economic circumstances are improving. It is considerably harder to maintain that confidence when households are confronted with higher fuel costs while financial markets are signaling greater inflation and borrowing risks.

The American economy has other longstanding pressures, including federal debt and fiscal deficits. But the conflict is adding a major new source of uncertainty at a particularly difficult time.

On Monday and Tuesday, the 60-day diplomatic timetable reached its endpoint without producing the comprehensive settlement that had been hoped for. 

Trump's declaration Tuesday that no talks are taking place or scheduled further underscored the diplomatic impasse. That leaves the United States facing an increasingly expensive stalemate.

The consequences are also global. Reuters reported that rising oil prices and bond yields were weighing on markets outside the United States, with European equities under pressure as investors assessed the possibility of prolonged energy disruption and inflation.

America therefore finds itself in an increasingly difficult position of its own making. And as long as the war continues, the economic bill for the United States will keep growing.