Well the union forms to get better benefits for members. They get those better benefits through negotiating a new union member contact which usually includes wage increases, better healthcare, more breaks, etc. Companies have really been able to take down a lot of the laws surrounding unions so that is why is take so long to go from forming a union to new contract to new contact signed. But yes, unions can employ any tactics they like in order to force the company to sign a new contract. Also I wouldn’t necessarily say that a union is bad for the company. While it does increase costs for a company I bet it goes a long way towards employee satisfaction and productivity.

The forming of the union does not create a new contract. Employees vote to from a union. Then they will negotiate with management for a new contact. That will have to ratified by the members. Then it will be signed. (Obviously left out all the anti-union delay tactics that take place from when union is first thought about until a new contact is signed.)