The comma does the heavy lifting and is unfotunately ambiguous.

Democrats vote down resolution calling for arms embargo on Israel, recognizing Palestinian state

This could easily mean:

Democrats vote down resolution that is calling for arms embargo on Israel and recognizing Palestinian state

Democrats vote down resolution that is calling for arms embargo on Israel while recognizing Palestinian state

In the case the resolution is unnamed in the headline:

Democrats vote down resolution thus calling for arms embargo on Israel and recognizing Palestinian state

Democrats vote down resolution thus calling for arms embargo on Israel, recognizing Palestinian state in the process