The United auto workers Union has reached a tentative agreement with General Motors to end the longest national strike involving the company in decades. But even if auto workers vote to accept the proposal, it won’t be hard for them to get some of the concessions they want most, experts say.

In addition to addressing concerns about wages and benefits, the strike is about getting assurances that unionized workers in the United States will continue to have a future at the company. Jobs are increasingly being given to temporary workers who face a difficult path to becoming permanent, being sent to factories without unions or in other countries.

However, global and national forces creating these problems can make it difficult to achieve these goals, experts say. Years ago, unions had more bargaining power because more American factories were unionized and controlled by the three big American automakers: GM, Ford and Chrysler. Today, Union workers compete not only with the company by moving factories to other countries, but also with non-Union factories in other States, many of which are run by foreign automakers.

John. Beck, an associate Professor At Michigan state University’s school of human resources and labor relations, tells TIME that employees are unhappy that while they made big sacrifices during the company’s 2009 bankruptcy, they don’t seem to benefit now that the company is more profitable. Plant closures, particularly the closure of Lordstown Assembly in Ohio in March, have deepened workers ‘ feelings of insecurity and their fears that the company does not value its workers, Beck says.

The strike, which began on September 15, is GM’s longest work stoppage since the 1970s, but workers are so determined to reach a better deal that they may choose to continue, Beck says. The new contract has not yet been publicly released, so rank-and-file members do not yet know the terms.

I think Theres a strong determination that Im seeingstill. If this strike is to last longer, I think There are a large number of UAW workers at General Motors who will support continuing to stay on strike, even if it takes a little longer to get what they want, Beck says TIME.

Harley Shaiken, a Professor who specializes in labor and globalization at the University of California, Berkeley, says workers feel it’s time to seize the moment when profits are strong. If you can’t win it back now, it won’t be easier in four years when they have to negotiate again, says Shaiken. They want to share and shape that future, not be left to it.

Its also a particularly critical moment, Beck says, because both employees and company executives know there Are major changes ahead for the auto industry. The future of electric cars and Autonomous cars will revolutionize the way factories operate, as it requires different parts, production times and number of workers than gasoline-powered vehicles.

However, he says everyone will have to wait and see what happens once the contract is released.