This is discussed in an article If You Are Impressed Into Service in the February 15, 2005 Watchtower. The primary points are :
- Put simply, Jesus was telling his listeners that if an authority compelled them into some kind of legitimate service, they should perform it willingly and without resentment. They were thus to pay “Caesar’s things to Caesar” but not overlook the obligation to pay “God’s things to God.”—Mark 12:17.
- Yet, on occasion, both in ancient and in modern times, Christians have felt that they could not in good conscience comply with government demands. ... On other occasions, Christians have felt that they could comply with what was asked of them. For example, some Christians feel that they can in good conscience perform services under a civilian administration involving general work useful to the community. That might mean assisting the elderly or disabled, serving as firefighters, cleaning beaches, working in parks, forests, or libraries, and so on.
Matthew 5:41 was not referring to either military service or conscription in the sense that one is conscripted into miltary service as a member of the armed forces. It was more like a form of tax whereby compulsory work could be demanded from the population on a regular or exceptional basis. An example would be Simon of Cyrene who was "impressed into service" to carry Jesus' stauron (Matthew 27:32).