The argument for free trade that commonly underlies neoliberal foreign policies can be made from the perspective of national security - it is seen by some policy analysts that countries that trade with each other are less likely to go to war due to the enormous cost of suddenly disrupting their trade abroad, particularly since they would be dependent on the world economy as a result of specialization and comparative advantage.

Adam Smith thought that all protectionist measures against free trade were scams on the public on behalf of producers, carried out in the name of nationalism. Even if the national economic interest had not been harmed by tariffs, he was opposed to them on the grounds that patriotism shouldn't be perverted by scoundrels to enrich themselves.

Classical economic analysis indicates that free trade increases the global level of output (thus, increasing the global standard of living) because free trade permits specialization among countries. Specialization allows nations to devote their scarce resources to the production of the particular goods and services for which that nation has a comparative advantage. The benefits of specialization, coupled with economies of scale, increase the global production possibility frontier. An increase in the global production possibility frontier indicates that the absolute quantity of goods and services produced is highest under free trade.

Free trade policies are often associated with general laissez faire economic policies, which can allow for faster growth. Laissez faire policies (the absence of government intervention in trade, entrepreneurship and investment) is often positively correlated with high per capita income. Economic Freedom and Per Capita Income

The quality and variety of produce available from international trade is much greater than the range that could ever be domestically produced in a single country. The wealthy always had access to such luxuries, but, before free trade the experiences available to the average person were dramatically limited. (For example, the history of tourism or the Spice trade).

If producers are located in different parts of the country than consumers then price-raising tariffs will cause social distress in one region, and wealth in another. This was the cause of the U.S. Nullification crisis.

The modern libertarian position simply argues that any trade restraint is immoral a priori, since restricting the rights of sovereign consumers to purchase foreign-made goods is outside the competence of legitimate government.

Increased trade is the best way to relieve extreme poverty throughout the world. Opposing free trade is tantamount to supporting economic injustice.

If food is purchased from the local farm it requires very little energy and possible no fuel to transport to the table. Delivering food produced on the other side of the world to a supermarket has an environmental impact because it requires a heavier use of fossil fuel in delivery from overseas.

The argument that a country could get 'locked in' to serving the needs of the world market in raw materials, and therefore not develop industrially was first advanced by Friedrich List in 1841, and received empirical support in the 20th century. It was discovered that African and Arab nations rich in natural resources (e.g. diamonds and oil) developed less slowly than those nations without such 'bounty'.

It was discovered that developed nations uncovering natural resources could suffer as a result of free trade. The massive capital influx to Holland after it started exporting oil increased prices in the famous "Dutch disease".

New Trade theorists challenge the assumption of diminishing returns to scale, and some argue that using protectionist measures to build up a huge industrial base in certain industries will then allow those sectors to dominate the world market. Less quantative forms of this "infant industry" argument against totally free trade have been advanced by trade theorists since at least 1848.

Many anti-globalization campaigners argue that free trade allows developed nations to exploit developing nations and to destroy local industry.

In the modern knowledge economy the goods and services 'exported' by developed nations are often intangible designs (such as 'medicinal formulae', 'trademarks', 'software', or entertainment content). The value of this Intellectual property (IP) is largely derived from the legal protection it enjoys from copying. Many advocates for the poor claim that the reason IP-rights are strongly protected in International trade is the economic power the developed world uses to protect the interests of their IP producers during trade negotiations. This is an especially emotive argument when applied in areas like AIDS medicine; WTO-signatory nations renounce the right to produce generic copies of life-saving pills, the only treatment widely affordable in developing nations.

Free trade allows companies the possibility of outsourcing the production of goods for domestic sale. The social, environmental, and labour standards imposed upon these companies can be less in foreign production than in domestic. Labour and environment advocates argue that Free Trade thereby creates the conditions that allow companies to circumvent domestic regulations, by producing in another jurisdiction.

As free trade increases, the balance of power shifts in favour of companies and away from governments. This is widely accepted, and considered to pose a threat to democratic self-determination by anti-globalizers.

Free trade hurts developed nations because it causes jobs from those nations to move to other countries, and accelerates the "race to the bottom". As well as reducing rich-country GDP through lost jobs, the argument goes that competitive pressures will undermine democracy by creating external pressures to lower wage demands, and legal protections like environmental and safety standards. The alleged "race to the bottom" is blamed on international competition to attract traded-goods production, which, with Free Trade, can be sited anywhere.