Leading article: Cause for excitement, hope - and also caution

The news that a team at the Oregon National Primate Research Centre has created dozens of cloned embryos from a 10-year-old rhesus macaque monkey will be read with interest across the scientific world. This is the first time scientists have been able to create embryonic cloned embryos using the DNA of an adult primate.

Such research has great significance. Scientists have successfully cloned several types of animals over the past decade, ranging from sheep to dogs. But before now it had never been done successfully with primates. Scientists will be eager to study Dr Mitalipov's techniques to see if they can be applied to human embryos, which are genetically similar to those of primates.

Success in human embryo cloning has been elusive. Claims from a South Korean laboratory in 2004 proved to be fraudulent. The one other documented example of a human embryonic clone died after a few days. And the work has not so far been replicated. But this latest research, which will be published in Nature this month, seems to promise a breakthrough.

This has exciting medical implications. It could open the door to the next stage of therapeutic cloning; the creation of stem cells for tissue, muscle and nerve transplants that will not be rejected because they will be made from the same DNA as the patient. People suffering from Parkinson's, Alzheimer's, heart disease, diabetes and spinal cord injuries could all potentially benefit.

But it also raises familiar ethical questions, in particular the spectre of human reproductive cloning. Attempts by the Oregon institute to produce live cloned primate births have failed. Embryos were implanted in the womb of 50 surrogate macaque mothers with no success. But there is still optimism among scientists that reproductive cloning of primates is possible. Some point to the fact that it took 277 attempts to create Dolly, the cloned sheep. But the flip-side of this optimism is that, if proved correct, it could help a maverick scientist to produce a cloned baby.

Creating human clones would raise a whole host of difficult moral questions. But the most powerful argument against the practice is that it would be inhumane to the cloned baby. Cloned animals have not been healthy specimens, with most suffering from genetic defects. As one of the "creators" of Dolly, Professor Ian Wilmut, has argued, cloning human beings would be dangerous and irresponsible.

How can we prevent this from happening? One of the suggestions in a United Nations report released yesterday is an international ban on all human cloning. Efforts to develop an international framework of regulation would be welcome. At the moment there is a serious risk that an unscrupulous scientist could exploit the different levels of legal protection that exist in different countries. But a total ban would be going too far because it would end cloning research by reputable scientists for purely therapeutic purposes.

Britain is at the forefront of cloning technology. Here, therapeutic cloning for stem-cell research is permitted under licence, but it is illegal to implant a cloned human embryo in a woman's womb. That is a sensible balance – and one that ought to be adopted internationally.

Reproductive human cloning is certainly a worrying prospect. But that is not a reason to fear or deprecate research of the sort that is taking place in Oregon. Nor is it an excuse for panic. Rather, it reinforces the need to build legal safeguards in our societies against the unethical application of these fascinating new scientific techniques.