As explained elsewhere in the International Estate Planning section, the decision to use one Will that covers multiple jurisdictions (i.e. multi-jurisdictional Wills) depends upon several factors.
One factor tipping in favor of using several single-situs Wills is that it promotes the testator’s privacy. By disposing of only assets located in a single country, the Will does not disclose the existence of assets in other countries. Please note, however, that using separate situs wills should not be used to facilitate estate tax evasion by a U.S. resident with assets in foreign jurisdictions.
Therefore, as a strategy, using several situs Will may help limit the enforcement of a claim by a foreign creditor by essentially enabling the testator to isolate assets in country A from creditors in county B.