JERUSALEM -- Red lines. When it comes to the Middle East, President Barack Obama is encountering them everywhere. They are painted on the ground as directional markers for visiting dignitaries, and they are in Obama's and Israeli Prime Minister Benjamin Netanyahu's foreign policy rhetoric as not-to-be-crossed warnings to Syria and Iran.
As Obama prepared to tour a missile battery that is part of Israel's Iron Dome defenses, an aide at the Tel Aviv airport directed the president to follow the red line on the tarmac.
"Bibi's always talking to me about red lines," Obama quipped, referring to Netanyahu by his familiar name.
Netanyahu has set "red lines" on Iran's nuclear development capabilities. Israel repeatedly has threatened to take military action should Iran appear to be on the verge of obtaining a bomb. The U.S. has pushed for more time to allow diplomacy and economic penalties to run their course, though Obama insists military action is an option. The issue has become a point of tension between the two allies.
Obama himself has used the phrase to describe limits that could prompt action against Syria's Assad regime. Any use of chemical weapons by Syria's regime, Obama has said, would constitute a "red line" that if breached could prompt direct U.S. intervention. It's a threat that could be tested amid new accusations that the regime used chemicals in an attack in a village in the north of Syria.
Referring to the painted red lines at the airport, Obama joked that it was "a psychological ploy."
Netanyahu replied: "It was minutely planned."
Obama received a rock star's welcome at Israel's international airport, where Israeli Netanyahu, President Shimon Peres and other dignitaries greeted him.
Netanyahu's new Cabinet, sworn into office just two days ago, lined up and excitedly shook hands with the president, who chatted with each one as he moved down the line.
There were no signs of the sometimes frosty relationship between Netanyahu and Obama. The two men smiled, joked and warmly exchanged pleasantries throughout the day.
In his speech at the airport, Netanyahu kidded Obama about his desire to explore Israel incognito. Netanyahu said he could arrange a trip to the bars and cafes of Tel Aviv. "We even prepared a fake moustache for you," he said.
Obama's traveling retinue is no small matter. The combination of aides and press who accompany the president makes for a massive grouping of followers who are simply part of the job of being president. But if Obama doesn't take notice, someone else in his family certainly does.
"Michelle teases me mercilessly," Obama confessed to Netanyahu, referring to his entourage during arrival ceremonies in Tel Aviv. "She says whenever she travels with me, it's embarrassing."
During a receiving line on the airport tarmac, Obama and Netanyahu stopped briefly to chat with Obama's deputy national security, Ben Rhodes.
Obama noted that Rhodes' brother, David, is president of CBS News.
"Sounds like a very incestuous relationship," Netanyahu observed, chuckling at the idea of siblings in power roles within the administration and the news media.
"Not if you watch CBS News," Obama replied.
It's no secret that Obama is left handed. But, he confessed to Netanyahu, it wasn't always easy to be a southpaw.
As Obama signed a guest book in Netanyahu's residence, the Israeli prime minister took note of Obama's distinctive inverted writing style.
Obama said that in Indonesia, where he lived as a child, using your left hand was considered bad manners and that instructors tried to correct it.
He said he stuck with it, "Even though I would get hit with the rulers."
Israelis and others awaiting Obama's arrival in Israel on Wednesday were surprised to see his signature black limousine sitting on the back of a flatbed truck.
The U.S. Secret Service said the vehicle suffered mechanical problems before Obama arrived but wouldn't say just what the problem was. Mechanics were examining the vehicle to figure out what happened.
The disabled limo was swapped out for a back-up, and Obama's busy itinerary in Tel Aviv and Jerusalem on Wednesday was unaffected. The Secret Service says its advance teams plan ahead for these types of glitches.
"This is why we bring multiple vehicles and a mechanic on all trips," said Secret Service spokesman Brian Leary.
The days before Passover are usually one of the busiest times in Jerusalem, with Israelis swarming stores and supermarkets to get ready for the holiday. But with Obama in town, downtown Jerusalem is eerily silent.
Well accustomed to the traffic jams caused by visiting world leaders, many Jerusalem residents stayed off the roads, fearing sudden closures, detours and backups.
"The whole city is upside down, we can barely walk and barely drive," said Jerusalem resident Sophie Casper. "Look at this. It's unbelievable!"
More than 5,000 Israeli police officers were deployed throughout the city, coordinating with American security officials to secure the roads Obama's motorcade will take over the next three days, said police spokesman Micky Rosenfeld.
Devora Avidan, a longtime Jerusalem resident, said the streets looked much different than when President Richard Nixon visited Jerusalem in the 1974 - the first-ever visit to the city by an American president. Then, Israelis were asked to line the streets to greet the president's motorcade.
Wednesday's scene was more similar to Yom Kippur, she said, the holiest day on the Jewish calendar, when Jerusalem's streets are empty of cars. "It was really nice."
When Obama visits the West Bank on Thursday, the Palestinians will send a message of music and peace.
Dozens of Palestinians will perform the traditional Dabka dance for Obama at the Palestinian Youth Center El-Bireh. The dancers were busy practicing on Wednesday.
Obama is set to meet with 120 youths chosen from four centers across the West Bank that are funded by the State Department's development arm, USAID. After that, he will meet with seven of them for half an hour.
Saja Abdelraheem, one of the lucky seven, said she will tell Obama she "has a dream" of seeing the conflict with Israel end during his term.
"I will ask him what can he do to make our dream come true, living in an independent state, ending our daily suffering," the 23-year-old said.
Mohammed Nazal, 28, who will also meet Obama, said: "I'm going to tell him that we want to live in peace and dignity, to work, build, move freely and in peace."