I came across a box full of my grandfather's belongings. He served in the US Army during WW2 and died shortly after my mother was born. He never discussed the war so we know very little. He left behind everything that's pictured here: http://imgur.com/a/F08oZ
If you're able to, I would appreciate some identification of these badges. I just find it odd that he has a Swastika trinket, Chinese currency, and a North African campaign badge.
It depends on what you consider a front. The US military didn't really use the term front as it instead used theaters, of which there were 3 major:
European
Pacific
American
There were Theaters within Theaters (Mediterranean, Middle East, Balkans, China/Burma/India, etc) and within them Campaigns. If you mean Campaigns, yes, there were definitely soldiers that fought in the North African, Italian, and the Western European Campaigns. It was common for soldiers that had completed the North African Campaign to either remain with their unit as it prepared for the invasion of Europe or be assigned to a new unit and fight in Sicily/Italy.
Moving onto your grandfather's awards. I'll make the best guess I can based on the image and it looks like he has duplicates of some. Ribbons, from bottom left going right and up:
European-African-Middle Eastern upside down
Asiatic-Pacific duplicate
Discussed below. Possible Philippine Liberation Medal?
GCM duplicate
Ribbon rack of top 3 awards in precedence at time of assembly.
The top left ribbon is really curious. It (pink/blue/yellow/pink) doesn't match any pattern of ribbon the US Military issued and looks very faded. It does, however, match a ribbon that the Republic of the Philippines issued out to the 33rd Infantry Division for its role in the liberation of the Philippines from the Japanese. That unit has a roster page you might want to check out.
He also has the Corps of Engineers device (twin towered castle) so it's likely he was an engineer of some capacity as well as being an expert marksman (iron cross wrapped in a wreath). The criteria for the American Campaign medal are pretty loose so it's entirely possible he served in North Africa as well as in the Pacific liberating the Philippines. The timelines are more than adequate for early North African (42-43) participation and then subsequent Philippines (44-45) participation.