With the bridges down, it's possible the NCR decides to call it off for a while. You don't [i]have[/i] to have them commit more forces. Things have not gone to plan for either side. Both the Yakima Republic and NCR are in need of reconsideration and a change of plans. Hathaway fucked the Yakima Republic over as much as he did the NCR when he took down the bridges. I'm looking forward to see how that bit of treachery is handled. Though I am worried I'll end up regretting it ;P