ALEXANDRA BEAN is the second, high-profile case in recent months of an Australian woman trapped in Libya. Such cases are delicate and, fortunately, unusual. Lost travel documents or a problem with foreign work permits are the usual reasons to call on consular assistance. But in recent years the demands for help have grown. Many of the nearly 25,000 Australians in difficulty seem to expect the government to rescue them. But diplomats cannot guarantee release of Australians arrested or imprisoned abroad. They can only attend trials, make jail visits, urge equal treatment and keep families up to date.