Chapter 25 7. why is there free trade between states in the US but not necessarily between countries

The United States Constitution gives the federal government the power to regulate commerce between states (Article I, Section 8). If Congress set up interstate trade barriers it could stifle our economy.

Since there is no such thing as an international constitution, countries are free to set up taxes and other barriers to trade with other countries.
Article 1 Section 8 gives Congress power to restrict and regulate commerce with both states and foreign governments.

However Section 9 sets limitations Congress can set on regulations and restrictions placed on states, that are not limited or applicable on foreign governments No Tax or Duty shall be laid on Articles exported from any State.

No Preference shall be given by any Regulation of Commerce or Revenue to the Ports of one State over those of another: nor shall Vessels bound to, or from, one State, be obliged to enter, clear, or pay Duties in another.

Despite the many benefits of free trade, arguments continue for restricting trade. One is that infant industries exist and require some protection to survive. These are industries that are too underdeveloped to achieve a comparative advantage or perhaps even to survive in global marketplace .

Some American trade laws target dumping, which occurs when a foreign firm sells its goods below costs in the US or at a price below what it charges in its domestic market. One goal of such dumping may be to drive American firms out of business, thus allowing the foreign firm to come back and impose higher prices on American consumers in the long