With the exception of a few airlines from the Middle East, for which high oil prices are helping to fund an expansion, airlines are in deep trouble.
这句话中间的插入语如何理解?  expansion是什么意思? 字典中的解释是  扩展  膨胀,但是用在这里,好像翻译不通顺?希望老师给解释一下!

Expansion is the process of becoming greater in size, number, or amount.

With the exception of a few airlines from the Middle East, for whichhigh oil prices are helping to fund an expansion(定语从句，修饰a few airlines from the Middle East, 对来自中东的航空公司来说，高油价为其扩张提供了资金), airlines are in deeptrouble.

http://www.economist.com/business/displaystory.cfm?story_id=11750444