Anime is a Japanese loanword used to refer to any sort of animation. Outside of Japan, in other countries, anime is generally considered to be a type of a cartoon. 

You can make a cartoon in a style similar to anime, but it can't truly be considered an anime. Why not, you ask? Animation differs by region. This can be because of the different techniques used, ideologies present, and resources available to each production or studio. 

Sure, anime can have various different styles and also emulate styles of other countries, and lines might sometimes be blurred when there are collaborations between studios from different countries. What makes them unique is the efforts of people, the people that come together to make them. Anime is what it is today thanks to the efforts made in Japan for the sake of the genre.

It's just like having your ethnic food in a foreign country. Some times it gets close but most of the time it'll have to acknowledge that it's not the same as if you had it in your home country. This may be due to a variety of reasons, like the availability of ingredients, skill of the chef, or even the recipe. While you can say it's ethnic food, it's just not the same.