For: A tried and trusted Western response to Slobodan Milosevic, and to plenty of other difficult people. Let the crisis drag on, let the fighting sort itself out. No risk to Western troops.
Against: The crisis continues. People keep dying, the stability of the Balkans deteriorates, the problem does not go away. If anything, the number of options becomes smaller as time goes on. Differences between the major powers get worse and exacerbate a bad situation.
2 Take it to the UN
For: The United Nations is the place to build consensus for any future action, and is the only place where a political solution can be created. If force is to be used, the agreement of the UN will make it legitimate, not just a unilateral gesture.
Against: The US in particular is very wary of the UN, and of limitations that it might place on Nato's freedom of action in this and future crises. In any case, given the political differences between the major powers over the issue, this option effectively means the same as option 1.
3 Intensify the pressure
For: Time is the key factor, so help create some while using plenty of threats to keep things moving. Put in place clear definitions of what Milosevic has to do and make it clear that if they are not met, airstrikes will follow. Lean on him in order to kickstart a political process.
Against: Remember Bosnia? Time is Milosevic's great ally. Let things drag on and nothing will happen. The KLA, in any case, have little incentive to negotiate unless independence is on the way. Full-scale war will still materialise.
4 Punitive Strikes
For: Using military force against Serb forces worked before, in Bosnia; Milosevic has shown in the past that he is not prepared to stand tough, and will back down under real pressure.
Against: It doesn't solve the po-litical problem. The basic dilemma over Kosovo is unresolved - can it stay as it is within Yugoslavia, or must it become independent? And what happens if Milosevic does respond - will the West be ready to escalate?
5 Heavy strikes
For: Strike Serbian targets with an intention to erase the country's military force, and force a solution on Belgrade. Prevent Serbian military forces from playing any role in Kosovo, and bolster the situation with a monitor force.
Against: Remember Bosnia? This will lead inevitably to ground forces in Kosovo, which neither the US nor Britain is happy about. Without it, a hornet's nest has been poked to little end. The fighting will carry on, and the KLA have the strategic upper hand. War is still a likely result.
6 Ground troops
For: In the end, territory can only be held by men on the ground, so move to it quickly before anyone is killed. Let the KLA and the Serbian government negotiate with Western forces in-between their keeping the peace - heavily-armed troops with plenty of backing from air, land and sea.
Against: This is peace-making, not peace-keeping, and it looks like nation- building. It didn't work in Somalia and it won't work here. The cost in Western lives could be high, and it would be an invasion, in effect, of a sovereign country. Ground troops means, probably, the Americans, and Washington won't go for it.