You may have noticed an exchange in the "How is it?" suggestions section about the absence of local mission from this site. If not, I hope you take a look and offer your thoughts. At the risk of oversimplification I'll venture a few thoughts on the relation of local and global mission as a former pastor and a former missionary.
It seems to me that global mission can be seen as an alternative to local mission. We feel the need to participate in the Great Commission, but it is easier and safer to give a few dollars so that others can do the mission work for us.
A second possibility is that global mission can be seen as a competitor to local mission. In that case, the more we do of one, the less we can do of the other. Each kind of mission has its advocates and there can be some tug-o-war between them. I've seen this happen between missions committees and youth pastors who are raising money for short term trips as well.
A third option is to see the two as synergistic partners. If both are seen as flowing from a heart that beats after God's heart in concern for those who are suffering the ill effects of a fallen world, they shouldn't be competitors. If our aim is to glorify God and love those made in His image, we cannot step over those nearest to us in order to focus on those far away. At the same time, we shouldn't ignore the 1.5 billion people who have not experienced the Gospel incarnate in a culturally relevant way.
Both local and global are vital. And, due to immigration and other factors, local and global are becoming more similar. What do you think?