I totally do not understand the technicalities. I thought I could take a deduction for the full amount of the foreign taxes paid. I have read the treaty and this paragraph confuses me:

"In addition to the normal rules for the avoidance of double taxation, the Convention contains a rule
not found in either the model or the existing convention for eliminating double taxation of United States
citizens who are residents in Canada. Under Canadian law, the credit for foreign taxes on dividends,
interest, and royalties is limited to 15 percent. Though the United States withholding rates under the
Convention on these forms of income do not exceed 15 percent, United States citizens are subject to
United States tax at normal progressive rates. Under the new Convention the United States agrees to
give Canada the primary right to any tax on such income in excess of 15 percent, with the United States
retaining only a residual right to tax."

My client is going back to Canada so I have to finish this today. Any helpful advice you have would be greatly appreciated.