Well, technically, Maven isn't based on developer "build scripts". It's based on the POM, which is more about defining what's located where and what the dependencies are.
To build a Maven WAR project, define the project as a WAR in your pom.xml file. When building inside Eclipse, right-click on the pom.xml in the navigator, and select the "Run As" menu. It should display a number of Maven goals. Usually "package" will do what you want.
An IDE is no substitute for an Intelligent Developer.