Even though fast food workers have staged several one-day strikes in the last 18 months, the protests have not swayed McDonald’s or other major restaurant chains to significantly raise their employees’ pay.

So on Thursday, the fast food workers’ movement wants to broaden its reach as it pushes for a $15-an-hour wage that restaurant companies say is unrealistic. In addition to one-day strikes in 150 cities across the country, the movement’s leaders hope to take their cause global. They say support protests will take place in 80 cities in more than 30 countries, from Dublin to Venice to Casablanca to Seoul to Panama City.

Over the last decade as American labor unions have declined in membership and power, they have increasingly turned to unions in Europe and Asia to help pressure companies overseas to stop battling organizing drives at their United States units. And now the fast food movement, underwritten by the Service Employees International Union, is embracing a similar strategy as it struggles to gain influence with the fast food giants.

“It’s a global economy, so they’re saying, ‘Why not go overseas to make it into a global fight?’ ” said Lowell Turner, a professor of international labor relations at Cornell University. “They’re trying to create a global protest movement.”