Tonight on PBS News Weekend, Israel mobilizes forces for a new ground defensive in Gaza,

capping one of the deadliest weeks since the ceasefire collapsed.

Then how Trump administration cuts to federal grants may affect groundbreaking breast cancer research.

And a largely forgotten tragedy from 40 years ago this week when police bombed a home in Philadelphia.

I've never heard of another case where a government has dropped a bomb on citizens in America.

This is not something that you can repair back to normal.

Good evening. I'm John Yang.

The Israeli military says it's mobilizing forces for a new ground assault in Gaza, after Palestinian officials said about 300 people died in waves of air strikes over the past 72 hours.

Officials say the objective of the new offensive, dubbed Operation Gideon's Chariots,

is to pressure Hamas into freeing the remaining hostages held in Gaza.

Even with the mounting fighting and preparations for more, cease fire talks resumed today in Qatar.

Jerry Shee is the Washington Post-Jurusalem bureau chief.

Jerry, this operation was approved earlier this month by the Israeli cabinet. Any sense of why the delay

or the distance between the approval and then launching it? Yeah, John. So basically what we've seen

is that Israeli Prime Minister Benjamin and Netanyahu said from the very beginning, when this vote passed on May 4th, that he was willing to send a massive military campaign into Gaza. This is a ground assault that would probably encompass about five divisions at 60,000 troops. And they would go in and they would take gradually increasing

amount of area within Gaza and drive hundreds of thousands of Gaza and south.

If Hamas were not to release hostages, now that was May 4th.

We've had a couple of weeks past since then.

And essentially, what we saw was this threat of this campaign being used

as a pressure tactic to force Hamas to come to the table from the Israeli perspective. Now, just in the

last couple of hours today on Saturday, we saw that the two sides were again meeting in Doha

in what appeared to be a last-ditch effort to see if they could reach a deal

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