Going the Second Mile

One of the books I'm reading right now is Engaging the Powers, by Walter Wink. In a chapter titled "Jesus' Third Way: Nonviolent Engagement" he takes a look at Matthew 5:38-42. He explains some of the background and implications of Jesus' instructions to turn the other cheek, give up the last garment, and go the second mile. All of these, he argues, are ways of nonviolent resistance (not nonresistance, as it may seem) against systems of oppression. I find especially interesting the explanation he offers for the third part: "if anyone forces you to go one mile, go also the second mile."
As you may know, this refers to the practice of Roman soldiers utilizing any common citizens to carry their packs. By law, they were allowed to do this, but they were limited (and, according to Wink, often disregarded the laws and regulations) - according to some records, the most a soldier could force someone to go was one mile. Jesus is teaching his followers to willingly go more than the required distance, when they are already being forcefully oppressed. And here's the part that caught my attention:

"But why carry his pack a second mile? Is this not to rebound to the opposite extreme of aiding and abetting the enemy? Not at all. The question here, as in the two previous instances, is how the oppressed can recover the initiative and assert their human dignity in a situation that cannot for the time being be changed. The rules are Caesar's, but how one responds to the rules is God's, and Caesar has no power over that.
"Imagine then the solider's surprise when, at the next mile marker, he reluctantly reaches to assume his pack, and the civilian says, 'Oh no, let me carry it another mile.' Why would he want to do that? What is he up to? Normally, soldiers have to coerce people to carry their packs, but this Jew does so cheerfully, and will not stop! Is this a provocation? Is he insulting the legionnaire's strength? Being kind? Trying to get him disciplined for seeming to violate the rules of impressment? Will this civilian file a complaint? Create trouble?
"From a situation of servile impressment, the oppressed have suddenly seized the initiative. They have taken back the power of choice. The soldier is thrown off balance by being deprived of the predictability of his victim's response. He has never dealt with such a problem before. Now he has been forced into making a decision for which nothing in his previous experience has prepared him. If he has enjoyed feeling superior to the vanquished, he will not enjoy it today. Imagine the situation of a Roman infantryman pleading with a Jew to give back his pack! The humor of this scene may have escaped us, but it could scarcely have been lost on Jesus' hearers, who must have ben regaled at the prospect of thus discomfiting their oppressors.
"Jesus does not encourage Jews to walk a second mile in order to build up merit in heaven, or to exercise a supererogatory piety, or to kill the soldier with kindness. He is helping an oppressed people find a way to protest and neutralize an onerous practice despised throughout the empire. He is not giving a non-political message of spiritual world-transcendence. He is formulating a worldly spirituality in which the people at the bottom of society or under the thumb of imperial power learn to receover their humanity." (Engaging the Powers, p. 182)