creating a war in archive view (why no entry in context menu? that view is not really intuitive) results in a war not deployable – jboss complains over not being able to create smth.
further research shows that libraries referenced in the build path (and not physically located in WEB-INF/libs/) are not included while creating the war.
deploying the application from the jboss ide includes those libs, though – but for productive use the app needs to be packed as war and thus include even libs only referenced ...

a workaround might be to create a fileset by hand – but because those libs are spread over several places it's a rather tedious task.