Some 32,000 Chicago teachers and school staff are striking on Thursday for smaller class sizes and more nurses, librarians, social workers and other support staff, along with increased spending to improve conditions in all schools. After many decades of Democratic Party attacks on public education, the crisis in the nation’s third largest school district has reached a breaking point.

Today’s walkout is the second since the fall of 2012 and part of a global wave of teachers’ struggles over the past two years. Since the beginning of the year, nearly a quarter million educators have struck in Los Angeles, Oakland and Denver, and participated in statewide walkouts in West Virginia, Arizona, the Carolinas, Kentucky and other states. In Croatia, 70,000 teachers are on strike over low pay and exploitative conditions and university workers may join them. In Jordan, 100,000 teachers recently concluded a one-month strike over low pay and on Tuesday, Algerian teachers walked out.

Chicago Public Schools teachers expressed their determination to beat back the decades-long attack on public education and teachers’ living and working conditions in a 94 percent strike vote taken in September, three months after their previous contract expired.

On Wednesday evening, the Chicago Teachers Union (CTU) House of Delegates voted to reject the city’s last offer and to launch the strike. Anticipating the decision, Mayor Lori Lightfoot canceled school beginning Thursday and until a tentative agreement is reached.

On Tuesday, CTU President Jesse Sharkey pledged that any strike will be “short-term,” a promise he reaffirmed at the CTU delegates meeting Wednesday evening.

Last weekend, Sharkey announced the union had found a “path to settlement” with the school board. As part of the “path”, the CTU had agreed to modify its demands for the needed library, social worker, nursing and other support staff.

Parks district and school staff workers were set to walk out with the teachers October 17, but the Service Employees International Union (SEIU) struck a last-minute bargain with Democratic Mayor Lightfoot to keep the 2,300 parks department workers on the job and help isolate the teachers. About 7,000 school staff on strike today are also under that union.

The teachers’ strike has broad support in the working class in the city and around the world. A poll conducted by the Sun Times and local television station ABC 7 found 49 percent of Chicagoans supported the teachers’ struggle.

The fight to defend public education itself is part of a broader struggle by the international working class to oppose decades of increased exploitation, including the destruction of public education, health and social services, that has sharply increased social misery while enriching the financial aristocracy. In Chicago, Los Angeles and many other major urban areas the corporate-backed assault on public education has been spearheaded by the Democratic Party.

On Wednesday morning, the Wall Street credit rating agency Standard & Poor’s warned that any increase to the CPS budget to accommodate the teachers’ demands could result in a downgrading of the district’s credit rating. According to the Chicago Tribune, Chicago has been paying upwards of $700 million per year to service public debts since 2008, roughly the same amount the state legislature has said it would provide to Chicago Public Schools annually.

Teachers must be warned: the CTU wants to push through an agreement that is wholly acceptable to the city’s Democratic Party establishment and the financial interests it defends.

Since the 1990s, Chicago has been at the center of pro-corporate “education reform,” including the closure of hundreds of neighborhood schools, the layoff of thousands of teachers and staff, and the expansion of networks of hundreds of privately run but publicly funded charter schools where the wages and benefits of the teachers and staff are far lower than those in CPS.

In 2012, the CTU shut down the seven-day strike by 26,000 CPS educators right at the point it was becoming a direct conflict with the Obama administration, which has spearheaded the attacks on teachers with its Race to the Top program that rewarded districts for introducing merit pay, lifting caps on charters and implementing punitive teacher “accountability” schemes based on the results of standardized tests.

The CTU shut down the 2012 strike, paving the way for then-mayor Rahm Emanuel’s plan to close 49 public schools and fire higher-paid veteran teachers. In exchange for this betrayal, the American Federation of Teachers was permitted to unionize the lower-paid charter schoolteachers and expand its dues base.

For months, the CTU has been working behind the scenes with Lightfoot’s administration to prevent a walkout and reach an agreement. However, it became clear in October that CTU officials would not be able to push through the contract terms demanded by the Democratic administration.

Allied with the Democratic Party and wedded to its austerity program, the AFL-CIO and other unions are doing everything they can to prevent a unified struggle by the working class that would challenge the economic and political monopoly of the corporate and financial elite.

Within a couple of hours of the announcement that United Auto Workers had reached a tentative agreement to move toward ending the month-long strike by 48,000 GM workers, the Service Employees International Union announced a deal with Lightfoot to prevent a strike by parks staff. The contract is a betrayal of parks workers who will be forced to pay sharp increases for health care coverage.

The collaboration of the unions to isolate the teachers from other workers’ struggles is a clear indication of the deep fear in the ruling class that the growing wave of walkouts among teachers, GM workers and other sections of public and industrial workers will culminate in a general strike.

Teachers can and must win this battle. But the lesson of the last two years of teacher struggles from West Virginia to Los Angeles is that educators must take the conduct of the struggle out of the hands of the Democratic Party-aligned and pro-capitalist unions. This means building rank-and-file committees in every school and neighborhood to organize a fight for what teachers, students and parents truly need, not what the corporations, Democratic Party and union bureaucrats say is affordable.

It is a grotesque lie to claim there is no money for public education and improved teacher salaries when tens of millions of dollars in tax cuts are showered on major corporations headquartered in downtown Chicago and 18 Illinois billionaires—many from the Pritzker family—made the Forbes list of the richest people in the world.

The only way to provide the resources needed to drastically improve the schools and neighborhoods, eradicate poverty and raise the material and cultural level of the whole population, is by conducting a frontal assault on the wealth and power of the super-rich to radically redistribute the wealth created by working people to meet their needs. That is the program of the Socialist Equality Party.

We urge teachers to subscribe to the WSWS Teacher Newsletter, which will do everything possible to provide Chicago teachers with a voice and perspective for this struggle, assist them in building rank-and-file committees, and link up their fight with autoworkers and other sections of the working class.