After Saudi Arabia, Israel, Rome and Brussels, Donald Trump's week-long odyssey comes to an end with the G7 meeting in the Sicilian town of Taormina. As has become a habit with such events, the picturesque location was turned into a bunker for the occasion, in anticipation of the protests that are also an annual feature.

It was 16 years ago in another Italian coastal location that the most violent demonstrations erupted, leading to the fatal shooting of 23-year-old protester Carlo Giuliani by police at the Genoa G8 (it was Eight before Russia was forced out in 2014 after its annexation of Crimea). Back in July 2001, the so-called "No Global" protesters were lashing out against the idea that a small group of powerful leaders could meet to mold the world as they sought fit. Less than three months later, the 9/11 attacks proved everyone wrong.

Now, these meetings seem more like annual emergency summits, amid rolling crises of economics and violence. Already high on the agenda, the issue of security took on a new immediacy after Monday night's deadly terror attack in Manchester that targeted teenagers at a pop concert. The two other topics expected to dominate discussion are climate and trade, both of which suddenly enjoy far less consensus than even just one year ago.

And yes, the uninvited guest that haunts Taormina: Vladimir Putin's Russia.

Taormina is located just south of the Strait of Messina, believed to have inspired the Greek legend of the two sea monsters Scylla and Charybdis that Homer included in his Odyssey epic, and gives us the expression of having to choose between two bad options, a "rock and a hard place," or as we say in French "plague and cholera."

Though Trump has only been away for eight days, he too has gotten an introduction to the many bad choices the world offers today. And when he returns home, at least two other hot potatoes (or rotten tomatoes?) await: the investigation into the leaking of sensitive information (this time not from him) to the U.S. press about the Manchester attack, and the FBI's expanding Russia investigation that now is reportedly focused on his own son-in-law and special advisor Jared Kushner.

And yes, the uninvited guest that haunts Taormina: Vladimir Putin's Russia. What role the Kremlin plays in Trump's own version of Homer's tale is yet unclear. But if Odysseus' fate is any indication, the only way to sail away alive from Scylla and Charybdis is to sacrifice part of the crew to the former. A lesson worth pondering as Air Force One heads back to Washington.