A direct loanword from English, used in similar contexts to the English term. Often carries a slightly formal or academic tone in Japanese.
彼の演説はパトリオティズムに満ちていた。
His speech was full of patriotism.
愛国心 is the everyday native Japanese word for patriotism, while パトリオティズム is a loanword with a more formal or academic feel.
パトリオティズム (patriotism) refers to love of one's country, while 国家主義 (nationalism) refers to a political ideology prioritizing national interest, often with a stronger or aggressive connotation.
Borrowed from English 'patriotism'.