Christianity Today reports on a problem that missionaries have faced many times: How to speak about the God of the Bible in a meaningful way to people with a different language and culture. In this case, it's something to consider even when the other person speaks English but has a different religion. The question is whether or not the term "Allah" can be an accurate translation of "God," when the God being spoken of is Jehovah of the Bible, the one true God. As we witness to Muslims, even in English, it's something we need to carefully consider.
The point is made in the article that the dictionary meaning of "Allah" is God; they're synonyms. So a strict translation would be using the terms interchangeably. That's a valid point, but it's not the only consideration because the goal is to communicate not just to translate. The terms are not only words with common definition, they are proper nouns referring to specific deities in each religion. The names, not just the terms, are laden with specific identity and theological content that refer to a specific being, and these beings are quite different according to each religion.
The point is to communicate not just translate, and I seriously doubt whether the term "Allah" can be disengaged from the specific name "Allah," the god of Islam. The dictionary terms might be interchangeable, but the names aren't interchangeable. And when we're discussing Christianity and Islam, it's the names we're using. Our evangelistic goal is to call Muslims from false worship of Allah to the God of the Bible, and it seems to me a strict translation of the terms doesn't adequately communicate the differences between the persons Allah and God.