In this verse the Romans discuss the possibility of changes being made to the treaty in the future.

If after these terms are in effect both parties shall determine to add or delete anything: Good News Bible begins with the connector “But,” which is helpful to introduce the contrasting idea of possible changes to the treaty. If after these terms are in effect may be expressed as “But if, in the future” (Good News Bible) or “But this treaty can be changed after it has become effective.” Both parties refers to the two nations involved in the treaty. The treaty can be altered in the future, as long as both the Romans and the Jews agree to the change.

They shall do so at their discretion may be expressed as “if both parties agree to do so.”

And any addition or deletion that they may make shall be valid: In many languages it will not be necessary to repeat addition or deletion. We may say simply “Any changes will be considered valid [or, binding]” or “The treaty, as amended, will continue to be valid [or, binding].”

An alternative model for this verse is:

• But after this treaty has become effective, it may be changed in any way, by adding or by taking away anything, as long as both parties agree to the change. The treaty, as amended, will continue to be valid.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.