The Israeli tanks that entered the periphery of Rafah early Tuesday stoked global fears that an offensive on Gaza's southernmost city could endanger the more than a million Palestinian civilians sheltering there.
The ground assault dimmed hopes of an immediate cease-fire deal that the US, Egypt and Qatar have spent months pushing for. In the hours before the attack began, Hamas agreed to a cease-fire proposal that the Israeli government swiftly rejected.
About 1.3 million Palestinians more than half of Gaza's population are jammed into Rafah and face the prospect of having to evacuate with no good plan for where to find adequate shelter.
Here's what we know so far about the operation and evacuation plan.
Where Will Palestinians go?
Now that Israel has begun ordering Palestinians to evacuate parts of Rafah, it is sending them to a patch of land whose current inhabitants say is little more than a makeshift tent camp with squalid conditions.
On Monday, Israel issued a warning to evacuate an area of eastern Rafah where approximately 100,000 Palestinians are sheltering. Israel encouraged the evacuees to move to Muwasi, an Israeli-declared safe zone that it says has expanded and will be equipped with field hospitals, shelter materials and other facilities. The United Nations and aid organisations say Muwasi is not ready to shelter the tens of thousands who might seek refuge there.
Muwasi stretches roughly 8 kilometres (5 miles) along the coastline from Gaza's southernmost city, Rafah, to its other major southern city, Khan Younis.
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Israel unilaterally declared the area a humanitarian zone early in the war, telling residents they would be safe there. According to the UN's agency for Palestinian refugees, UNRWA, Muwasi is now home to more than 450,000 displaced Palestinians, including many who arrived in recent months as Israel has intensified its ground offensive in central and southern Gaza.
An Associated Press journalist saw dozens of Palestinians arriving in northern Muwasi on Monday. Although there were dozens of empty tents nearby, there were few signs of widescale preparations being made to accommodate the large influx of evacuees that was expected. Other Palestinians across Rafah, even those outside the evacuation zone, have decided to head to central Gaza or to Khan Younis instead of Muwasi.
UNRWA didn't assist in preparation efforts in Muwasi, as it didn't want to entice people to move to an area that isn't prepared to accept them, said Scott Anderson, the agency's Gaza director. However, UNRWA will provide aid to new evacuees who arrive there moving forward, he said.
Residents say toilets are scarce and there is little running water in Muwasi. Many relieve themselves in walled holes they dig outside of their tents to avoid long queues at the public latrines and maintain privacy. Palestinians say they sometimes wait hours to collect drinking water from the tankers that deliver it to various locations in the camp.
A number of stalls in the camp sell tent-building equipment, canned foods and basic vegetables such as tomatoes and potatoes at inflated prices. A kilogram (roughly 2 pounds) of potatoes goes for around USD 6 a high price for the vast majority of people.
Building a large tent from wood and nylon costs about USD 500, people there said, while buying a ready-made version costs about double.
Jan Egeland, secretary-general of the Norwegian Refugee Council, condemned the call for people to head to Muwasi.
The area is already overstretched and devoid of vital services, Egeland said, noting that an Israeli assault on Rafah could lead to the deadliest phase of this war.
What does the Rafah operation mean for humanitarian aid?
UN officials say an attack on Rafah will collapse the aid operation that is keeping the population across the Gaza Strip alive, and potentially push Palestinians into greater starvation and mass death.
The Rafah crossing has a main route for aid entering the besieged enclave and the only exit for those able to flee into Egypt. Early Tuesday, Israel seized control of the Gaza side of the crossing, saying militants had staged attacks from the area.
Both Rafah and Kerem Shalom, the other main aid entry point, have been closed since a Hamas mortar attack killed four Israeli soldiers. Though smaller entry points still operate, the closure is a blow to efforts to maintain the flow of food, medicine and other supplies that are keeping Gaza's population alive.
Some entry points have been opened in the north, and the US has promised that a port to bring in supplies by sea will be ready in weeks. Bringing aid into Gaza through Rafah would likely be impossible during an invasion.
Why does Israel says Rafah is critical?
Since Israel declared war in response to Hamas' deadly cross-border attack on October 7, Netanyahu has said a central goal is to destroy its military capabilities.
Israel says Rafah is Hamas' last major stronghold in Gaza, after operations elsewhere dismantled 18 out of the militant group's 24 battalions, according to the military. But even in northern Gaza, the first target of the offensive, Hamas has regrouped in some areas and continued to launch attacks.
Israel says Hamas has four battalions in Rafah and that it must send in ground forces to topple them. Some senior militants could also be hiding in the city.
Hamas continues to launch projectiles from Rafah. Hamas launched half a dozen mortars and rockets toward Kerem Shalom again on Tuesday.
Israeli strikes continued throughout Tuesday in Rafah, largely in the city's eastern section. Plumes of thick black smoke rose over the horizon after several of the strikes.
What has the international reaction been?
The Egyptian Foreign Ministry said Tuesday that the "dangerous escalation threatens the lives of more than a million Palestinians who depend primarily on this crossing as it is the main lifeline of the Gaza Strip, referring to the Rafah crossing.
Egypt, a strategic partner of Israel, has said that an Israeli military seizure of the Gaza-Egypt border which is supposed to be demilitarized or any move to push Palestinians into Egypt would threaten its four-decade-old peace agreement with Israel.
The US has urged Israel not to carry out the operation without a credible plan to evacuate civilians and says it still hasn't seen one. The US previously said Israel should use pinpoint operations inside Rafah without a major ground assault.
The president doesn't want to see operations in Rafah that put at greater risk the more than a million people that are seeking refuge there, White House national security spokesman John Kirby said Monday.
Political Calculations
The current operation, which is more limited in scope, could be a tactic by Netanyahu to appease ultranationalist and conservative religious partners in his government. They have threatened to pull out of the coalition if he signed onto a cease-fire deal without an operation in Rafah.
Netanyahu's critics say he's more concerned with keeping his government intact and staying in power than the national interest an accusation he denies.
One of his coalition members, Finance Minister Bezalel Smotrich, has said that accepting a cease-fire deal without a Rafah operation would amount to Israel raising a white flag and giving victory to Hamas.
Now that the Rafah operation has begun, Netanyahu risks further isolating Israel and alienating its biggest ally, the U.S.
His vocal refusals to be swayed by world pressure and his promises to launch the operation could be aimed at placating his political allies even as an Israeli negotiating team was in Egypt attempting to revive the possibility of a cease-fire.