The fragile calm between the United States and Iran has shattered.

A new exchange of strikes has pushed the two countries back toward open confrontation, while the world's energy markets are confronting a far more immediate danger: the possibility that violence around the Strait of Hormuz could disrupt one of the most strategically important oil routes on the planet.

The escalation began with a fresh U.S. wave of attacks against Iranian targets. U.S. Central Command said the strikes focused on Islamic Revolutionary Guard Corps assets including air defenses, radar systems, maritime equipment, mine-laying capabilities and communications infrastructure along Iran's southern coast.

Washington said the operation followed recent Iranian attempts to threaten commercial shipping through the Strait of Hormuz as well as attacks directed at American personnel in the region.

Iran responded within hours.

Tehran said its forces launched what it called a decisive operation against U.S. facilities around the Middle East, with Iranian officials and state-linked media reporting attacks involving missiles and drones against targets in Jordan, Iraq, Bahrain and the United Arab Emirates. Authorities in Jordan, Kuwait, Bahrain and Iraq reported intercepting incoming fire.

The speed of the retaliation underscored how quickly an already dangerous dispute has entered a new phase.

For several weeks, the conflict had experienced a relative lull. That pause has now disappeared, and there is no obvious diplomatic off-ramp capable of stopping the next round of attacks.

The most sensitive flashpoint is the Strait of Hormuz.

The narrow waterway connecting the Persian Gulf with the Gulf of Oman is a critical artery for global energy markets. Any prolonged disruption could affect crude supplies, shipping costs, insurance rates and inflation far beyond the Middle East.

Markets reacted almost immediately.

Brent crude climbed above $97 a barrel in early trading before giving back part of its gain, reflecting fears that oil and gas flows could remain disrupted for an extended period.

That reaction is significant because energy markets are already under pressure from geopolitical uncertainty.

Oil prices do not need the Strait to be completely closed for traders to become nervous. The perception that tankers face greater risks can be enough to raise shipping costs and push buyers to secure supplies earlier than usual.

And the danger is no longer theoretical.

Two supertankers attempting to leave the Strait were hit by projectiles in quick succession, according to maritime security reporting cited by Bloomberg. The United States has also adopted what Axios described as a new “tanker for tanker” policy, under which U.S. forces have attacked Iranian tankers.

Every additional incident increases the possibility of a self-reinforcing cycle.

Iran threatens shipping.

The United States strikes Iranian military or maritime assets.

Iran retaliates against U.S. facilities or regional allies.

Washington then threatens a larger response.

And the next attack becomes harder to contain than the one before it.

That is precisely what global markets fear.

The human cost has added another explosive political dimension.

Iranian authorities accused the United States of striking a residential area during a wedding celebration in Kuhestak, in southern Iran's Hormozgan province. Iranian officials and the Red Crescent reported that civilians were killed and dozens injured, including women and children. Reuters reported that Iran said five people were killed and dozens wounded; other reports gave varying casualty figures.

The United States has said its military operation was directed at military and maritime capabilities rather than civilian gatherings, while casualty claims from the scene have not been independently verified in full.

Regardless of the competing accounts, the incident creates an enormous political obstacle to de-escalation.

Civilian casualties can harden public opinion, reduce room for compromise and increase pressure on leaders to respond forcefully.

President Donald Trump has signaled little interest in backing away.

After the latest strikes, he said he was not trying to force Iran back to the bargaining table and indicated that he was satisfied with the U.S. strategic position. He also warned that America would continue striking Iran if Tehran retaliated.

Iranian leaders are sending the opposite message: any attempt to restrict the country's ability to move or export oil risks triggering additional retaliation.

The result is a dangerous contradiction.

Both sides appear convinced that pressure can force the other to retreat.

But each new act of pressure gives the other side another reason to escalate.

The economic consequences could become severe if the conflict spreads beyond military targets.

Higher oil prices would put immediate pressure on transportation and manufacturing costs. Energy-intensive industries would face rising expenses, while consumers could eventually see the impact through gasoline, heating and food prices.

Central banks would also face a difficult choice.

If higher oil prices reignite inflation, policymakers may have less room to cut interest rates even if economic growth weakens because of the geopolitical shock.

That combination—higher inflation and weaker growth—is one of the most uncomfortable scenarios for financial markets.

The conflict is also widening geographically.

Israel has continued striking Hezbollah positions in southern Lebanon, while Hamas has warned that an already fragile ceasefire in Gaza could collapse after renewed Israeli military activity.

What began as a confrontation centered on Iran and the Strait of Hormuz is therefore becoming a broader regional crisis.

For markets, the biggest question is no longer whether Iran and the U.S. will exchange another round of fire.

They already have.

The question is whether either side can stop the retaliation cycle before it spreads into a sustained regional war.

And for oil traders, shipping companies and governments around the world, one narrow waterway has suddenly become the place to watch.

Because what happens in Hormuz may determine where energy prices—and global inflation—go next.