In a picture the UFT distributed on Twitter, President Michael Mulgrew and AFT President Randi Weingarten wear red today to show solidarity with teachers on strike in Chicago.

When teachers in the country’s third-largest school district go on strike, the question is only natural: Could the same thing happen in New York City?

The answer is yes, in theory. But there are a host of reasons why New York City teachers probably won’t follow their Chicago colleagues in trading the classroom for the picket line any time soon. Here are several issues to consider:

Only some of the issues in dispute in Chicago are also under contention in New York City. Like Chicago’s teachers, city teachers would like a pay hike. They’ve have gone without substantial raises for several years. And like Chicago’s union, the UFT is very concerned about  some elements of the reform agenda that the Obama administration has advanced, particularly about the use of student test scores in teacher evaluation systems. That issue has caused acute tensions between the UFT and the Bloomberg administration for more than a year, keeping the city so far from complying with the state’s new teacher evaluation requirements.

But New York City teachers don’t have to grapple with many of the issues Chicago teachers face. The union contract already contains class size limits, even if the union says they are sometimes skirted. Recall rights for laid-off teachers have been in place for decades. And the school year has long been 180 days.

And because the policy agenda that Mayor Rahm Emanuel brought to Chicago last year has been solidly in place in New York City for nearly a decade, city teachers and their union have had more time to adjust and reach compromises. While the Bloomberg administration and the UFT haven’t agreed on the technical points of teacher evaluations, they have struck a broad agreement on the concept that student test scores can play some role in ratings. They have already agreed to extend the school day and given schools options to add even more time. And their 2005 contract created an Absent Teacher Reserve with no time limit on how long teachers can draw salaries without occupying permanent positions after losing their old ones — a policy that city officials now want to change but so far have not been able to.

The UFT more resembles 2009′s Chicago Teachers Union than today’s. Like Chicago’s union until recently, the United Federation of Teachers has long been dominated by a single caucus that has been willing to work with city officials to reach compromises on issues such as teacher placement, extending the school day, and even evaluations. The compromises have angered some union members, who have criticized the union and its leadership for not adequately defending teachers’ rights.

But unlike in Chicago, where the Caucus of Rank-and-File Educators, or CORE, seized power in 2010, there hasn’t yet been a serious threat to Unity’s power. In the last union elections, the caucus’s candidate for president, Michael Mulgrew, won with 91 percent of the vote.

There are people who want the situation to change. One group of teachers within the union is taking more than inspiration from Chicago’s union, this year forming a caucus they named the Movement of Rank-and-File Educators, or MORE. The group hasn’t yet formalized a policy agenda but members say they object to the UFT’s positions on charter schools, school closures, and mayoral control.

Another group is also trying to find a foothold in union leadership, with a different set of aims. The group, Educators 4 Excellence, has conscripted teachers to study and push for changes to policies about teacher hiring, firing, and evaluation rules. Often, the group’s recommendations mirror policy positions advanced by the city or education reform groups. Its first campaign, for example, was to call for the abolition of “last in, first out” seniority layoff rules, which the UFT has staunchly defended.

Both MORE and Educators 4 Excellence have seen members elected to union chapter leader positions at individual schools, but so far, neither group has penetrated the Unity party. That doesn’t mean they won’t in the future, though, particularly as the education policy paradigm in the city shifts under a new mayoral administration starting in 2014. Mulgrew is up for reelection in 2013, six months before New Yorkers will elect in a new mayor.

There’s no point in striking a lame-duck mayor, or a brand-new one. There are no contract negotiations underway in New York City. That’s not because teachers have a current contract; they don’t. But the old one stays in effect until a new one is negotiated, and neither the union nor the Bloomberg administration has much incentive to talk. That means the union is unlikely to get a new contract until the city gets a new mayor.

A new contract won’t be automatic, of course. The new mayor will want to use negotiations to assert his or her policy agenda, and depending on who is elected, that agenda could be difficult for the UFT to stomach. But even if talks grow contentious, it would take a long time for relations to decay to the point that a strike might be called. In Chicago, for example, Rahm Emanuel has been mayor for a year and a half. And insiders say they doubt any of the city’s likely mayoral candidates would take as tough a line against the union as Mayor Bloomberg has.

State law doesn’t favor strikes. The same law that gives New York State employees the right to bargain collectively also levies stiff penalties for strikes. Public employees who strike are liable for a day of pay in addition to the day’s pay that they lost by not working. Union leaders can even be sent to jail. So while striking isn’t technically illegal, the law is set up to guard against it, and the cost could stop or impede a teachers strike even if one is one day deemed necessary.

Still, New York City teachers are looking westward. Just because a strike isn’t on the radar in New York City doesn’t mean Chicago teachers won’t have any impact on the UFT and its members. Chicago’s strike is putting simmering issues on the public radar and, by illustrating for city officials across the country the high stakes of advancing aggressive reform policies, potentially creating an opening for unions elsewhere to push back against their districts.

Some city teachers are already taking action to support their Windy City colleagues. Some pledged to wear read in a show of solidarity today, a campaign that union officials joined in. The UFT distributed photos of a meeting where ever attendee was wearing red and of Mulgrew and AFT President Randi Weingarten posing together in red shirts. The union is planning to pass a resolution supporting Chicago’s teachers tonight at its executive board meeting, and additional action could take place when the full complement of union delegates meet on Wednesday. And the MORE Caucus, along with Occupy supporters and other labor backers, is holding a rally this afternoon in Union Square.

“As teachers in New York who are also victims of the national assault on our unions and our schools, we need to stand in solidarity with our brothers and sisters in Chicago because their fight is our fight,” said Megan Behrent, a city teacher and longtime activist around education policy issues.