Is it legal for Unions to strike in solidarity?

[SteelPenguin]

What I mean is this...

I was reading an article on the Writers Guild strike, and how they are one of the most powerful unions because they're essentially impossible to replace. They can't offshore the writing to India or China, like they could say a manufacturer, so they have more leverage. They refer to this as 'knowledge base' jobs in the article, and mention a few other types that can't be replaced such as health care or things with highly specific training.

So my question is, is it legal for different unions to strike in solidarity. For instance, lets say a Teacher's Union allied with the union representing the local waste disposal workers. That way whenever the teachers would strike, so would the garbage workers, and vice versa. Or even national unions striking in solidarity...

What if the UAW went on strike again. Would it be legal for every teacher nationwide, and the Writers Guild, and Teamsters, and Garbage workers...nationwide...to strike in solidarity? Is that legal? Sort of like the nation wide strikes you see in other countries where the workers have far more protections.

Even if it is illegal why doesn't it happen here? Are we all just now so far in debt nobody is willing to risk anything to have all of us stand up and say "enough is enough"?

[BadgerLaw2010]

1. There is a No Strike Clause in most contracts. You can "strike" but you'll lose your job.

Teamsters have a clause that allows them to not cross picket lines, and their jobs are protected by federal law in those circumstances. That means actual picket lines, though.

In Hollywood, both the DGA and SAG (directors and actors) have No Strike provisions.

[SteelPenguin]

2. Second Question Then

I ask because I've never been unionized myself...

What's the benefit of a union that can't use a strike as a method of wielding power?Shutting down the means of production so to speak.

What would happen if every member of the DGA and SAG, to keep it in terms of Hollywood, refused to work until they had that clause which allows them to not cross picket lines like the Teamsters?

What would happen if every teacher in the country picketed until they had those kinds of clauses?

Didn't the people who first started going on strike so many years ago, basically get fired for striking, and they had to fight for their rights as workers?

Lets take Everytown USA. What if the teachers and garbage workers both just took to the picket lines, even with a working contract, and refused to work until they had those provisions in their contracts that allowed them to strike in unison? What would happen? What if it was an entire state or nationwide? If every teacher in the country hit the streets until they could strike in unison and guarantee a higher minimum payscale for teachers or whatever...even if it was 'illegal' wouldn't they still have more power?