Every year, several hundred Americans are arrested abroad on drug charges. Persons caught with illegal drugs in a foreign country are subject to the drug laws of that country, not those of the U.S.; as always, ignorance of the law is no excuse. In many countries, the burden of proof is on the accused to show that he or she is innocent of the charges.
Some Americans take advantage of an offer of an all-expenses-paid vacation abroad in exchange for carrying a small package in the luggage. When, to their surprise, they are caught, the fact that they did not know that there were drugs in that package will not reduce the charges against them.
Every aspect of a drug arrest abroad can be different from U.S. practice. For instance:
As with any arrest of a U.S. citizen abroad, consular officers perform a variety of services (see Arrests Abroad, above). For more information about arrests abroad, see http://travel.state.gov/travel/tips/emergencies/emergencies_1199.html.