Just blowing up a suitcase nuke with conventional explosives would yield a dirty bomb however, 5000 jihadist turned snipers among our cities would cause more terror and mayham than anyone could imagine. Just look at what two did to the east coast not long ago. There is a storm brewing IMHO among the swarthy type but they are like independent truckers, you can't get two of them to agree on anything.
These guys don't shoot very well and we have a heavily armed population. 5000 snipers we can handle. Nuke's would be another issue, but I doubt they've got 20 and certainly not in country. Though they may have a few.
LOL - Somebody out there really needs to adopt that as a tagline...
You said: "you can't get two of them to agree on anything."
Thank heavens for that!