Identify problem-solving techniques that would use as well as a conflict-resolution strategy that would effectively solve the problem below.

Supertowne (a fictitious organization) is a nationwide superstore.  The board of directors and leadership has decided to expand Supertowne by adding stores to both Canada and Mexico.  Their long-range plans include expansion into many other countries.  You are charged with the development of a store in Canada.

You have several team members from both the U.S. and Canada working with you. For the most part your team works together with very little conflict.  However, one of your U.S.-based employees, Matt, has been arguing with Mary, a Canada-based employee. Mary expects Matt to provide certain officials with gifts (along the lines of expensive liquor or cigars).  Mary has explained that this is common practice when doing business in Canada.

Their arguments have escalated rapidly and recently grew into a shouting match during which Matt accused Mary of expecting Supertowne to participate in bribing officials. Mary denied the accusation.  Both are now refusing to work together. Their conflict is impacting your entire team and causing team members to take sides.