For a start, the bickering between allies over what is to be done immediately to staunch the bleeding on the military front will have to be replaced by a consensus - of which so far there has been little sign.
Beyond that, scales will have to fall from eyes as to the limits of what is possible for the UN forces. Above all, new insights will have to be developed out of the past muddle about the role of the Bosnian presidency army - so far deliberately handicapped in its task of defending the Bosnians (wrongly labelled Muslims) by Western policy.
Even to list these challenges is to demonstrate how tall an order this is. Yet one has to live in hope. Supposing, by a great leap of faith, that the policy-makers do at last begin to get their act together, what would be the main components of a workable fresh approach to the worsening crisis?
First, and immediately, the military position must somehow be stabilised, More bluntly, Gorazde must not become the soft touch for the Bosnian Serbs which Srebrenica and now Zepa have proved so fatally to be. A sufficient reinforcement must be put into the enclave at least to prevent another humiliating and tragic walk-over.
It would not, of course, be a long-term solution to anything, but at least it would provide a breathing space while the second and third phases of a new policy are put in place. At least it would allow the UN soldiers to withdraw - in due course - with dignity.
That second part should be to revise the role of the UN in the area. Some people persist in talking as though the choice for the UN were all or nothing. This is nonsense. As in other parts of the world the civilian agencies of the UN can play a vital humanitarian role even while fighting is going on. And blue-helmet troops can do a valuable job in seeing their convoys through and brokering local ceasefires - as British and other UN soldiers are doing at this moment in Central Bosnia.
The third part is the most controversial. It is to start on a programme of building up the strength of the Bosnian presidency forces by giving them the same access to arms to defend themselves as their enemies possess in abundance.
This need not start with the tanks and artillery they desperately need, although that will have to come. Even more desperate is the need for simple ammunition and for trucks to move their forces around.
Once this process of reinforcement started the UN could begin planning an orderly and dignified withdrawal from its near-impossible role of maintaining the unsafe "safe havens" and concentrate on much more limited but very worthwhile humanitarian work.
Meanwhile, a reinvigorated Bosnian army could try its own hand at keeping the remaining eastern enclaves. If it failed in due course with the more isolated enclaves, that is no more than what is going to happen anyway if policy is unchanged.
But with Sarajevo the Bosnian army cannot be allowed to fail. The strangulation of Sarajevo just must be prevented - as it certainly could be by presidency troops with heavy arms and with a helping hand from Nato air support.
Faced with real opposition the Bosnian Serbs would encounter the conditions which so far they have never had to face - conditions in which they would know from the outset that they would get as much as they gave in terms of casualties and lost ground.
That is the one way first to a ceasefire, then to talks and then at last to negotiations about who holds what part of the hapless Bosnian nation. It is a path that should have been followed long ago.
Out of war will come peace. Out of pretending there is a peace to keep will only come prolonged killing, brutality and war.
That is not foretelling the future. It is describing the present. This day the policy must be changed, or many, many more will die.
The writer is chairman of the Foreign Affairs Select Committee and Conservative MP for Guildford.