Your scenario requires a level of ineptitude that is impossible to accept. The complete collapse of our intelligence systems at every possible level, so this mysterious enemy can pop off nukes with abandon and leave absolutely no tracks? America surrendering to a mysterious enemy which never reveals itself - presumably even after the surrender, and who then control America remotely? How, from a Facebook account with their privacy settings set to “don’t tell”?
In the event we really were up against it somehow as badly as you portray, all that would happen if we “surrendered” is that our military nuke, space, scalar and other assets would go black and wait. And once enough information was gathered, the eventual military response would be absolute, and this mysterious enemy would cease to exist once and for all.
Thing is though, there is no mysterious enemy anywhere. All is known, all is exposed to those involved. The players are all under the lights. Not on television or the Net, no. But very well known, and tracked, and watched, by all involved, every moment of every day. That’s reality.
As a partial list I submit the following as examples of the "collapse of our intelligence system":
Pearl Harbor Attack
The Korean invasion
The Entire Vietnam War
The Bay of Pigs Invasion
The Tet Offensive
The Yom Kippur War
The Iranian Revolution
The Soviet Invasion of Afghanistan
The Collapse of the Soviet Union
The Indian Nuclear Test
Iraq's invasion of Kuwait
Bombing of the World Trade Centre in 1993
The 9/11 Attacks
WMD in Iraq
Boston Marathon Bombing
("All is known, all is exposed to those involved." ?)
"so this mysterious enemy can pop off nukes with abandon and leave absolutely no tracks?"
I submit that it is self-evident that the blast itself will "leave absolutely no tracks." Certainly not tracks that can be investigated, analyzed, and effectively reacted to in time.
" a mysterious enemy which never reveals itself "
The Internet demands come to multiple establishment networks "over the transom." Al Jazeera, for example, has little interest in tracking down the source. Who would be doing the tracking down? The Muslim brotherhood which has already penetrated the inner sanctum of the White House? We cannot dismiss the treachery possible from a fifth column.
"the eventual military response would be absolute,"
Any subsequent military response would be at the cost of another American city.
"Thats reality."
That "reality" has failed so many times that my back of the envelope list demonstrates that it is hardly reassuring and certainly not dispositive of what the collective inventive minds of a army of devious jihadist can contrive. If I am wrong life is sweet, but if you are wrong
Please remember, this scenario is simply to illustrate the absolute necessity of preventing Iran from getting the bomb. This is only one of the baleful consequences which flow from that calamitous event. Others have been discussed such as the destruction of the present balance of power in the Persian Gulf and the ignition of the nuclear arms race in the Arab world. The point of the vanity is that we should not permit ourselves to be distracted from Iran to Isis.