All for freedom and for pleasure
Nothing ever lasts forever
Everybody wants to rule the world
--Tears for Fears
In the political context, nationalism is a policy of treating one's own country as the proper sphere of political influence. It is marked by shared feelings of of superiority over other countries and actions to preserve what is perceived to be the country's collective culture and interests. An expression of nationalism is protectionism in its various forms, such as tariffs, immigration restraints, and wars justified by some form of purported national interest.
Globalism, on the other hand, is a policy of treating the entire world as the proper sphere of political influence. It is marked by efforts to subordinate feelings about native country in favor of the collective interests of all people. An expression of globalism is expropriation of economic resources to support initiatives alongside other countries, such as humanitarian efforts like global warming or even shared military causes.
Both nationalism and globalism are forms of statism (a.k.a. socialism) as their associated policies must be enforced by the strong arm of government. Stated differently, neither of these are natural states of man, because they require offensive force to enact. The only question involves the scope of government force. Does government-sponsored aggression stop at a country's borders? Or does it extend across the planet?
Currently it seems that the two major political party platforms are being built with either nationalist or globalist planks.