In the United States, one spouse cannot prevent another spouse from obtaining a divorce. Briefly, the party who wants a divorce must formally notify the other spouse pursuant to state laws. The person serving the divorce papers can be a private process server or sheriff. That service provides the other spouse with the opportunity to object and represent their own interests in the proceeding. The service provides proof for the moving party that the other party was given notice. If the spouse refuses to show up for the scheduled divorce hearing the original filing spouse has the right to proceed and request a divorce.
You should arrange a consultation with a well recommended attorney who specializes in family law and divorce if possible.
In some instances, you may be able to get a "default" judgment if the defendant refuses to sign the petition papers. This can be a serious disadvantage for the person who doesn't want to sign, as the judgment and any monetary awards will surely not be to his/her liking.