Corrected entry: When the Enterprise is under attack by the Son'a, the Son'a fire a subspace weapon to open a dimensional tear in space. Geordi then says that the warp core is acting as a magnet, so they eject the core and blow it up to seal the tear. But then Geordi tells a bridge officer that the Son'a could do it again and they are "fresh out of warp cores". If however the warp core acts as a magnet to the subspace tear, a second similar attack by the Son'a would not affect the Enterprise because it is now without its warp-core.
Gary O'Reilly
11th Sep 2004
Correction: No, the tear wouldn't chase after the Enterprise, but it'd still expand rather quickly, and leave a nasty big hole in subspace. And without a warp core they have absolutely no chance of outrunning one.
Gary O'Reilly