We're not implying.  We're saying you just can't in this particular case.

DTA helps alleviate double taxation but the mechanisms differ depending on the residency of the taxpayer, the type of income it is, and you need to refer to the specific article for the details.

A DTA usually confers to a treaty partner the primary right to tax an income.  For certain types of income, a treaty partner may be assigned the exclusive right.  In spite of these, the Saving Clause allows the US to tax US residents, citizens, and certain former citizens without regard to the DTA unless surgically excepted.  Under some DTAs, such as the one with Germany, certain income would need to be re-sourced for foreign tax credit purposes and this gets complicated.  While DTAs usually override the Code, it is not always the case; when there are conflicts, the last in time principle would generally apply.

As you can see, DTA is a very technical subject matter.  If you are not familiar with the international provisions or do not deal with this type of returns often, you may consider referring these to an experienced expat tax specialist instead.