Services & Investment The Office of Services and Investment (SI) is responsible for U.S. trade policy relating to services, investment, and digital trade, including the negotiation, implementation, monitoring and enforcement of bilateral, regional and multilateral agreements. Trade and Investment Policy Watch. Trump’s Trade War Timeline: An Up-to-Date Guide. Chad P. Bown (PIIE) and Melina Kolb (PIIE) February 14, 2020. Trade and Investment Policy Watch. Unappreciated hazards of the US-China phase one deal. Chad P. Bown (PIIE) January 21, 2020. Beginning with NAFTA, U.S. trade policy made a radical and reactionary break with the past. In effect, it responded to the changing circumstances by allowing U.S. corporations to shed the economic and social responsibilities of being “American.”