AMNA NAWAZ: Welcome to the "News Hour."

The war with Iran has entered its third week.

Shipping traffic through the critical Strait of Hormuz remains effectively shut off, and the shockwaves to the global supply chain of oil are being felt here at home with gas prices on the rise.

GEOFF BENNETT: President Trump himself is demanding help from U.S.

allies to secure the strait.

Meantime, Israel has announced yet another front in the war, a ground operation in Lebanon.

Nick Schifrin starts us off.

NICK SCHIFRIN: In Southern Beirut today, an Israeli bombardment.

By day, in the capital's southern suburbs from where Hezbollah operates, the buildings have been obliterated, this block left smoldering and shattered.

And, today, for the first time since the war with Iran started, Israel launched what it called limited targeted ground operations in Lebanon's south.

The new offensive has already emptied southern cities and sparked the evacuation of more than one million people, who will not be allowed to return to their homes any time soon, Defense Minister Israel Katz warned today.

ISRAEL KATZ, Israeli Defense Minister (through translator): Prime Minister Netanyahu and I have instructed the IDF to act and destroy the terror infrastructure near the border in Lebanon, just as it was done against Hamas in Gaza.

NICK SCHIFRIN: And Israeli and American strikes continue to target Iran.

Israel today admitted it struck Iran's electricity grid, but said it was colocated with an intelligence center, while U.S.

strikes continue to target Iran's missiles and drones, whose launches are down more than 90 percent.

DONALD TRUMP, President of the United States: This is a paper tiger that we're dealing with now.

It wasn't a paper tiger two weeks ago.

It's a paper tiger now.

NICK SCHIFRIN: In Washington, President Trump described Iran as increasingly weak, but he acknowledged that he approached half-a-dozen countries for help securing the Strait of Hormuz, through which 20 percent of the world's oil and natural gas flows and Iran has effectively shut with its attacks.

DONALD TRUMP: Many of the Europeans get quite a bit.

South Korea gets 35 percent.

So we want them to come and help us with the strait.

Some are very enthusiastic and some are less than enthusiastic.

And I assume some will not do it.

I think we have one or two that will not do it that we've been protecting for about 40 years at tens of billions of dollars.

NICK SCHIFRIN: But, in Europe, that implicit threat failed to inspire immediate action.

British Prime Minister Keir Starmer: KEIR STARMER, British Prime Minister: So, we're working with all of our allies, including our European partners, to bring together a viable collective plan.

NICK SCHIFRIN: And a European official goes further, telling PBS NewsHour that, while the war is ongoing, no European countries are interested in deploying military assets to help secure the Persian Gulf.

DONALD TRUMP: Why are we protecting countries that don't protect us?

And I've always felt that was a weakness of NATO.

We were going to protect them, but I always said, when in need, they won't protect us.

We don't need them, but it's interesting.

I'm almost doing it, in some cases, not because we need them, but because I want to find out how they react.

NICK SCHIFRIN: The U.S.

isn't only appealing to European allies.

Today, Japanese Prime Minister Sanae Takaichi said she had not received any formal U.S.

request yet.

And the country that buys the most Iranian oil and imports the most oil from the Gulf is China.

President Trump was supposed to leave for Beijing to meet Chinese President Xi Jinping spending two weeks from today.

But, today, he confirmed he wanted to delay the trip by a month.

DONALD TRUMP: We're speaking to China.

I'd love to, but, because of the war, I want to be here.

NICK SCHIFRIN: And so the war's effects continue to spread.

Brent crude prices remain above $100 a barrel, and American gas prices are nearly $1 more expensive per gallon than just one month ago.

Iran is trying to maintain that financial pressure with attacks on Gulf oil facilities.

Today and over the weekend, it struck a key Emirati oil export terminal.

But Iran also continued to target Gulf civilian sites, today, a fuel tank next to Dubai International Airport, the busiest in the world for international travel.

These attacks will continue and Iran will not negotiate, Foreign Minister Abbas Araghchi said today.

ABBAS ARAGHCHI, Iranian Foreign Minister (through translator): We're not asking for a cease-fire.

This war must come to an end in a way that it will not be repeated again.

NICK SCHIFRIN: And despite previous declarations of victory, that mirrors President Trump's vow to keep the war going until the U.S.

won't have to go back and repeat it again.

For the "PBS News Hour," I'm Nick Schifrin.