So how did he do?
Well, final results might be years away, but early returns are encouraging: a number of U.K. and Israeli businesses are now planning visits, Nutter said; the mayor of Tel Aviv wants to collaborate on student exchanges; a major Israeli venture-capital fund wants to bring a corresponding trade mission to Philadelphia.
Scratch the surface, more seeds seem to be germinating.
Eden Shochat is emblematic of scores of Nutter's listeners, who invariably say they came away with a new appreciation for, and knowledge of, Philadelphia.
A partner in Aleph, a $140 million Tel Aviv venture capital fund, Shochat is no naïf, but until Nutter's visit last week Shochat had no idea that Philadelphia had a port or a constellation of medical research centers.
And the mayor's description of the city's renaissance has Shochat thinking of suggesting that next year's GeekCon, an annual gathering of tech-heads and computer geeks, consider Philadelphia as opposed to New York City.
"I am always amazed by the magnitude of change one person can make," Shochat said.
Closer to home, Michael Brown was representative of the Philadelphia-area businesses that traveled with Nutter, hoping to make overseas connections.
"It was definitely worth it," said Brown, president of Environmental Construction Services Inc., of Philadelphia. "It was top-notch. They rolled out the red carpet for us in both countries, and it was all to do with the mayor."
The logistics of the trip were straightforward enough: Nutter, Deputy Mayor for Economic Development Alan Greenberger, and five staffers would host a delegation of Philadelphia-area businesses, first to London, then on to Tel Aviv. The tab for Nutter and his team was picked up by Select Greater Philadelphia, the marketing arm of the Greater Philadelphia Chamber of Commerce. Everyone else was on their own.
If extended travel reveals character, it showed Nutter to be hardworking, focused and affable, even while operating on little or no sleep.
Despite his credentials, he carried his own luggage and was ever ready to grab that of an overwhelmed staffer.
And there was serious luggage.
Luke Butler, Greenberger's chief of staff, carried a backpack stuffed with 60 pounds of promotional material. In other bags, there were dignitary gifts - ties, miniature Liberty Bells, silver plates, and, for the real luminaries (Tony Blair, Shimon Peres, etc.), personalized Phillies jerseys.
The trip showcased Nutter's young staffers, an eclectic group that included Butler, an unflappable 30-year-old native of the United Kingdom with degrees from the London School of Economics and the University of Pennsylvania; Shinjoo Cho, 35, a classically trained pianist, who after nine years in the city's Commerce Department is now director of international business investment for the city; and Desiree Peterkin-Bell, Nutter's communication director, who has worked in the past for U.S. Sen. Cory Booker and New York Mayor Michael Bloomberg. (Asked her age, Peterkin-Bell smiled.)
The team also included Lauren Walker, 27, special assistant to Nutter, and Kait Privitera, a photographer.
They were, of course, simply in supporting roles to the star of the drama.
Nutter's own take on the trip was that it was a success but merely a step in the right direction.
It was not lost on him that many of those he met had little or no current knowledge of the city he was selling.
"I think we have a pretty unique package to offer," he said. "But we need to increase our marketing and promotion budget for the city."
He said the city needs to reach out to other regions as well - Asia, South America, the broader Middle East.
That could entail more trade missions, Nutter said. Certainly, more foreign travel is in the works: on Friday, the mayor's office announced that Nutter would travel to Panama with Vice President Biden to review the Panama Canal expansion project, which will allow significantly larger ships to call on U.S. ports, including Philadelphia.
"To be an international city, we have to be able to have an international conversation," Nutter said. "That's how you become an international city. By acting as an international city."