It seems to me they could perfectly well leave Mars to Europe. In the new colony, the space suits would be designed by the Italians, and the Mars rovers be built by the Germans. Scottish engineers would develop innovative solutions to every problem and deploy precision instruments made by the Swiss. The French would provide the catering, but the Belgians would make all the desserts. The English would be the administrators. The Portugese would set off to explore the planet, while the Spanish would set up a resort on the edge of the colony to attract tourists from Earth. The Irish would figure out how to brew stout in the hydroponics plants, and they would develop the constitution. A redheaded Irish woman would be the first President of the Republic of Mars.
It would fare much better than the American colony on the other side of Mars, which would extravagantly waste its local resources, and import almost all its consumer goods from Earth without being able to pay for them. Its main source of income would be Japanese tourists who would save for a lifetime to get to Disneyland Mars. Its undemocratic christian leadership would barely acknowledge the existence of any other colony.
However, they and the other colonies will all be united in making jokes about the stupid earthlings.