Perhaps a build management tool would be helpful to allow the developers to package and deploy a WAR to a server. Our organization did a proof of concept of this using Hudson and Ant.
Hudson checks out the project using a CVS tag or branch name, builds the WAR file, and then deploys it to the server. Since Hudson is web-based, I can access it remotely. Since Hudson's server is within our company network, it can check out the project and deploy it, creating a layer of abstraction between the developers and the server.
You could also argue that you and your team need some sort of secure VPN access to the server. But the build management tools would be more secure and also come with more benefits.
http://javatools.wordpress.com/2007/02/23/hudson-a-continuous-build-system/