The hearing aimed to “question the wisdom of relying for national economic policy on a single, specific model when alternatives are available.”——The Economist
I was wondering if "for" is necessary here. Could I remove it?
You can rely on a certain plant for your nutritional needs. Similarly, a nation can rely for national economic policy on a single model. Another way to say this is that a nation relies on a single model for its economic policy.
So, when you use "rely" you use "on" to tell us what you're relying on.
You use "for" with "rely" to tell us why you rely on something.
I rely on my car for transportation.
I rely on my friends for conversation.