When I got married I had the same question, so I wrote the IRS to ask them. Here is what they had to say:
A joint return generally cannot be made if either spouse is a
nonresident alien at any time during the tax year. However, if one spouse is a nonresident alien who was married to a U.S. citizen at the end of the year, the spouses can choose to file a joint return. [color=red]If you do file a joint return, you and your spouse are both treated as U.S. citizens for the entire tax year.[/color] For more information on this choice see our Publication 519, U.S. Tax Guide for Aliens,
And I still had some questions and here is some more information:
For the year that you make the choice, you and your spouse are required to file a joint income tax return, however, you and your spouse can file joint or separate returns in later years. [color=red]Once made, the choice to be treated as a resident applies to all later years unless suspended or ended in one of the following ways;[/color] (1)revocation, (2) death, (3) legal separation, or (4) inadequate records. Please refer to Publication 519, U.S. Tax Guide for Aliens, for detailed information regarding this issue
While you are married you cannot use the filing status of single. You would use either the married filing joint, married filing separate, or you may be eligible to use the head of household filing status if you meet the requirements. Please refer to Publication
501, Exemptions, Standard Deduction, and Filing Status, for detailed information regarding this issue.
As you can see they went into great detail and off my topic question but that additional information may help you here… So basically what they mean is that once you decide to file your taxes with your wife in the US, then you must do it each year after that unless for reasons they stated you want to change it. Because your wife has a social security number it may be different but I doubt it… So long as you are living out of the country it should apply to you. Of course if you decide to immigrate to the US then she would be required to file. You can go to there website if you have further questions for them, and don’t forget if you do ask more info and get it post it back here for the rest of us! See irs.gov/taxlaw
I hope this helps!