The answer to this question turns on balancing risk against efficiency.
If you are an international individual, having property in more than one country, then you may dispose of your assets using either a multi jurisdictional will or using several single-jurisdictional wills. The single-jurisdiction wills typically apply, of course, only to the property located in a single jurisdiction.
On the one hand, taken individually, each single jurisdiction will is easier to draft, and thus will likely result in less attorney fees for you to pay. However, the major advantage of you using a single multi-jurisdictional will is that it can help eliminate a court proceeding after your death because of potential confusion and controversy. For example, multiple situs wills may lead to controversy when they do not effectively delineate the property to which they apply to. In the worst case scenario, complicated “conflict of laws” issues can arise that can lead to protracted and expensive litigation to sort out the administration of your estate after your death. In that case, your beneficiaries would surely have desired that you had implemented a multi-jurisdictional will that when properly drafted may have avoided the litigation. Confusion can also arise when using several wills for the different countries in which you hold propertywhen the various wills do not clearly indicate which personal representative is in charge with which particular assets and/or responsibilities.
The bottom line is that if multiple single situs wills are not drafted correctly they can cause unforeseen and often undesired results. In the worst case, a single-situs will can be interpreted as revoking the other single situs will(s) causing some or all of a your property to pass through intestate succession (law that applies when there is no valid will) upon your death. Intestacy is undesirable because the assets are divided and transferred according to the government’s laws, rather than by your testamentary intentions.