Relativism and Imposing One's Values

Philosopher Bill Vallicella has a brief but brilliant post on relativism.  The title of the post declares the main point--A Relativist Cannot Rationally Object to the Imposition of One's Values on Others.  Here are the opening lines:

The following argument is sometimes heard. "Because values are relative, it is wrong to impose one's values on others."

But if values are relative, and among my values is the value of instructing others in the right way to live, then surely I am justified in imposing my values on others. What better justification could I have? If values are relative, then there is simply no objective basis for a critique or rejection of the values I happen to hold.  For it to be wrong for me to impose my values, value-imposition would have to be a nonrelative disvalue. But this is precisely what is ruled out by the premise 'values are relative.'

Either values are relative or they are not.  If they are relative then no one can be faulted for living in accordance with his values even if among his values is the value of  imposing one's values on others.  If, on the other hand, values are not relative, then one will be in a position to condemn some forms of value-imposition.  The second alternative, however, is not available to one who affirms the relativity of all values.