The problem is that life will never be "normal" again, or at least I pray that it won't be. They inevitably will be greeted by many well-meaning "Welcome homes" and "I bet you are so happy to be home", which will most likely be returned with a forced smile, a simple thank you, while internally pondering the meaning of home. Please don't think that they aren't grateful that God has brought them safely back to family & friends. It's this weird mix of being happy to be reunited with family & friends but at the same time, realizing that they have left a huge part of their heart across the ocean.
They will be cold all the time. Tears may well up in their eyes a lot more frequently than they used to. They will have a hard time spending money. They may cry at the sight of the people or the sound of the language from the countries where they served. As they move back to college, they may take weeks to unpack because they are overwhelmed with how much "stuff" they have. They will desperately want to share stories from their summer, but may not know how to do so. They will sit in their classrooms but their minds will be in a place far away. Mundane tasks will seem meaningless. They will wonder if God can really use them here like He did over there. If He can really work in as big of ways here as He did there.
But, God. He heals the brokenhearted. He told us this wouldn't be easy. He wants us to share His story & our stories. He extends so much grace to us & wants us to do the same for others who may not understand. He says for everything there is a season. He has us here for the time being for a reason: to make disciples of ALL nations. He has brought the nations to our backyards. He sends us encouragers & people to encourage. He may even send us people from the same people groups that we worked with overseas.
For those welcoming these students back, please love them & show them a lot of grace. Sit down and ask to hear their stories & listen. Pray with them and for them as they navigate life back in the U.S. & as the Lord shows them next steps. Pray about how God wants to use you to serve the nations both here & overseas.