Should Public Sector Employees Be Allowed to Strike

Should public-sector unionized employees be allowed to strike under any conditions? Public sector employees include police officers, fire fighters, federal employees , and teachers. First off a unionized employee is anyone who has joined a workers union. Everyone can join a union as long as he or she receives a salary from an employer. Public sector unionized employees are those employees who belong to an workers union. Even part-time, casual and temporary employees can also join a union.   However employees who represent their employers in their dealings with the staff for example those acting at the management level, such as foremen and forewomen can not join workers union. This is because they are considered as employers.
According to “A trade union (or labor union) is an organization of workers who have banded together to achieve common goals in key areas, such as working conditions. The trade union, through its leadership, bargains with the employer on behalf of union members (rank and file members) and negotiates labor contracts (Collective bargaining) with employers. This may include the negotiation of wages, work rules, complaint procedures, rules governing hiring, firing and promotion of workers, benefits, workplace safety and policies. The agreements negotiated by the union leaders are binding on the rank and file members and the employer and in some cases on other non-member workers.
One may ask why a union is so important to public sector workers. A union is basically a tool that employees can rely on to improve their working conditions and to protect their rights. Do all public employees have a better pay, a paid leave or do they receive assured promotions? I wonder whether the answer is a resounding YES as to whether all these employees have a greater number of fringe benefits such as group insurance, retirement plan, sick leave, etc.
If the answer is No does it mean that all public employees don’t need such things? I believe that...