Conquest differs from occupation. The Bible's 'When you come to the land ...' is not about conquest but about occupation.
It is the occupation forces that must recognize the dependency of every person of the health of the land.
"Those are the two poles between which a competent morality would balance and mediate: the doorstep and the planet. The most meaningful dependence of my house is not on the US government, but on the world, the earth. No matter how sophisticated and complex and powerful our institutions, we are still exactly as dependent on the earth as the earthworms. To cease to know this, and to fail to act on upon this knowledge, is to begin to die the death of a broken machine. In default of man's personal cherishing and care, now that his machinery has become so awesomely powerful, the earth must become the victim of his institutions, the violent self-destructive machinery of man-in-the-abstract. And so, conversely, the most meaningful dependece of the earth is not on the US government, but on my household -- how I live, how I raise my children, how I care for the land entrusted to me.
"... To assert that a man owes allegiance that is antecedent to his allegiance to his household, or higher than his allegiance to the earth, is to invite a state of moral chaos that will destroy both the household and the earth."
Wendell Berry, Some Thoughts on Citizenship ..., in The Long Legged House, 1969; quoted in Slow Money, page 158.
Berry is almost right. He cannot however really take the nation-state out of the equation. Sheviit/shemitta recognizes what Berry instinctually understands and elevates his sentiment to frame it as the fundamental predicate behind God's covenant with the people of Israel. As far as the Bible is concerned the meaning of faithful service to God is the proper stewardship of the land. We serve God not in acts of conquest, not in the prosecution of His holy wars, but in the stewardship that comes with our occupation of His land as we come to that land granted to us by Him. Without this national and this cosmic articulation with the household and the planet, Berry's prescription is just so much wishful thinking that, as it inevitably does, just ends in a sad sigh.