As a resident alien you do have to file an income tax return if your gross income is more than the filing requirement.
For 2013, the amount is
for married, filing jointly:
under 65 (both spouses) $20,000
65 or older (one spouse) $21,150
65 or older (both spouses) $22,200
for married, filing separately:
any age $3,900.
Yes, you can file jointly with your spouse.
If your spouse is not a citizen or resident alien you must choose to include all of her worldwide income to file jointly. See http://www.irs.gov/Individuals/International-Taxpayers/Nonresident-Spouse-Treated-as-a-Resident
Whether or not the pension from Jordan is subject to US income tax is a bit more complex question. There is not an income tax treaty with Jordan and the US, so you will have to apply the US rules to that pension. The fact that this pension is not taxed by Jordan does not affect whether or not it is taxable to the US.
In general, pension income is taxable to a US resident or citizen to the extent that the money in the account is not due to contributions made by the taxpayer and those contributions were subject to US tax when the amount was contributed.
Rules for pension taxation are discussed at length in the publication at http://www.irs.gov/publications/p575/index.html
When I have prepared tax returns for residents with a pension from another country it is the tax treaty that can be used to not have the pension subject to tax. Otherwise, the general rule is that a pension is taxable (except to the extent amounts have already been taxed, as mentioned).
"In general, you can recover the cost of your pension or annuity tax free over the period you are to receive the payments. The amount of each payment that is more than the part that represents your cost is taxable "
So, whether the pension is fully or partly taxable primarily depends on whether you had a cost or not for the pension. You may need to analyze the facts to make this determination.
If your spouse does not have much worldwide income it will be more beneficial to file a joint return than a separate return.
Please ask if you need more discussion or clarification.