The key
word there is "dependent". Dependencies are what Maven does best.
If both projects are under Maven control, you can build the dependency using one of the repository-related goals (such as "mvn install") and it will copy the target and POM info to your repository where you can list it as a dependency in the other project in the usual way.
However, WARs can't, strictly speaking, depend on other WARs.
J2EE doesn't work that way, regardless of what Maven might allow. Most commonly what people really mean is that they have common code, in which case it's usually recommended to make that common code into a JAR and make that JAR a dependency of both WARs.
Of course, if what you really want is simply to ensure that you have built the latest versions, you can define a POM project which includes both WARs as dependencies.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.