Chris Nelson writes on Pakistan in the wake of Bhutto's death:

At the risk of sounding callous to the predicament of the Pakistani people... for the world, key questions tonight are whether the military will be able to keep control of the nuclear weapons arsenal...and, is there a risk that Pakistan will literally blow-up into uncontrollable chaos, and so spill-over into the region?

Answers, based on hurried consultation this afternoon with authoritative US sources, are "reassuring" in a crude sense: the nukes are under control, nothing happening now, including the likely imposition of martial law by President Musharraf, is expected to change that situation for the worse.

Experts warn that if the current violence extends from Karachi, Ms. Bhutto's PPP party stronghold, to Lahore, home of the military leadership...that will be Musharraf's decision-point.

Suspicion as to the killer/killers must include lower ranking Pakistani military...so look to see if renewed attempts are made on President Musharraf and other political figures.

The assumption is that Al Qaeda and/or Taliban were involved in today's events...and if so, it would be "logical" for further assassination attacks to be launched against Pakistan's leadership.

Indeed, as unwelcome in principle as martial law is, the immediate chaos and risk of violence in Pakistan's major cities probably means it is the best of a bad situation, short and even medium-term.

Setting aside the nukes, does that situation pose a threat to the region? Stay tuned for the next 24-48 hours. Again, the prediction, or conclusion, however reluctantly given, is based on a martial law response and the assumption...presumption...that "order will be restored" however painfully.

Regional risk assessment must include India's reaction. In recent months, the rising uncertainties in Pakistan have caused India to beef-up troops along the Kashmir border.

Our experts note that bilaterally, professionals on both sides of the India/Pakistan border have been working to reduce tensions, so for now, the risk is seen as coming from Kashmiri separatists trying to capitalize on the situation by somehow provoking India.

Continued domestic unrest...and/or the need to pull troops from the Afghan border...clearly will not help US interests, or regional stability.

What about the US goal of free elections as scheduled Jan 8? Seemingly impossible, for obvious reasons. And if re-scheduled, the PPP must designate another candidate.

This may prove either impossible or essentially meaningless, since politics in Pakistan is intensely "personal" and Ms. Bhutto was really all the PPP had to offer.

Her husband may seem the logical pick, but his well-earned reputation for corruption and mendacity exceeds even her record, during her second term...so not a happy choice.

"Saudi Arabia's" candidate, former Prime Minister Nawaz Sharif, or Imran Khan, are expected to try to move to the front of the political pack, but our experts...looking at a situation which, obviously, can change overnight...do not think either gentleman will be able to capitalize (one almost uses the word "profit") from Ms. Bhutto's murder.

For now, Nawaz is saying he won't be a candidate so long as Musharraf stays in power, so one of the things we need to find out is whether he has ties to the military...and not just to Riyadh...and is hoping to see what comes his way.

Flawed as she was, Ms. Bhutto was really the only "candidate" the US had with the capacity to make and enforce some kind of a deal with Musharraf, and to set in motion a return to something resembling normal political life and liberalization.

Right now, US policy is in shambles. Is there no hope?

Our experts say if some semblance of order can be restored, and something resembling a real election scheduled, and held, perhaps former caretaker Prime Minister Qureshi...or, more likely, Chief Justice Chaudhry, fired by Musharraf...may gain mass public support as an alternative to military rule.

Recall that Chaudhry's sacking, which set off the dramatic "lawyers revolt", saw well-dressed professionals in the streets...by the thousands. It was seen at the time as "the collapse of the center" which might herald a collapse of the Musharraf regime.

But for the next day or so, perhaps through the weekend, basically "all hell will break loose"...not a pretty picture, and a real tragedy in the Shakespearean sense, an historic change with unforseeable consequence.

More soon.