What is the greatest mission field?

Some of Jesus' last words were to wait for the Holy Spirit to come and then to be his witnesses in Jerusalem AND Judea AND Samaria AND the ends of the earth.  It isn't an either/or commandment but a both/and proposition.  Jesus wanted his disciples to live out and preach the kingdom in all of those places.  I hear a lot of people say "why go to the ends of the earth when there is so much spiritual need right here in America" and I know us missionary types have been guilty of telling everyone that we all need to focus on the ends of the earth because America at least has a chance to receive Good News.  The truth is that the Great Commission should be translated "as you are going, make disciples...", so all mission fields are valid and important.

It think it really all boils down to intentionality and going where the Father says and doing as the Spirit leads.  I feel like if we were really in tune and listening to the Lord that there would be a lot more than 2% of the mission force working among unreached people groups in the 10/40 window and many more people at home living a missional lifestyle reaching out to neighbors, co-workers, and the foreigners that God has sent to live among us.  What would happen in the US and the ends of the earth if we did what Jesus said and waited for the Holy Spirit to come and then went out witnessing to the world everything we know about Christ and His kingdom in Jerusalem AND Judea AND Samaria AND the ends of the earth?  Let's be missional; the time is short and we only get one life to steward well.