Saddam's nuclear programme was destroyed by Israel in 1981 and thank god for that - just imagine what this guy would have done if he had nukes. In principle, there should be a world free of nuclear weapons, in practice we should prevent radical regimes which threaten to destabilise world order to develop nuclear weapons. So, although it is not a welcomed situation, it would not change much if a country like Belgium would develop nuclear weapons.
However, countries like Iran, Syria, Myanmar, Sudan, Libya, Venezuela, and Cuba should be prevented from acquiring nuclear weapons. If it was possible, the US should have made stronger efforts to prevent Pakistan and North Korea from acquiring nukes in light of their irresponsible proliferation policy (nuclear assistance to radical regimes: Iran, Syria, Libya)