Reporters routinely describe Ron Paul's foreign policy views as "isolationist" because he opposes the promiscuous use of military force. This is like calling him a recluse because he tries to avoid fistfights.
The implicit assumption that violence is the only way to interact with the world reflects the oddly circumscribed nature of foreign policy debates in mainstream American politics. It shows why Paul's perspective is desperately needed in the campaign for the Republican presidential nomination.
As the Texas congressman has patiently explained many times, he supports international trade, travel, migration, diplomacy, and cultural exchange. Furthermore, he supports military action when it is necessary for national defense—in response to the 9/11 attacks, for example.
The inaccurate "isolationist" label marks Paul as a fringe character whose views can be safely ignored. Given the dire consequences of reckless interventionism, that clearly is not the case.