Final answer:
The groups who opposed the establishment of Israel in 1948 and fought in the First Arab-Israeli War are Palestinians, Muslims, and Arabs. Despite their efforts, Israel, with support from Britain and the United States, won and expanded its borders.
Step-by-step explanation:
The terms that describe those who fought to stop the formation of the country of Israel by starting a war in 1948 are Palestinians, Muslims, and Arabs. During this period, known as the First Arab-Israeli War, neighboring Arab states including Syria, Saudi Arabia, Lebanon, Iraq, and Egypt sided with Palestinian Arabs to oppose the newly declared State of Israel.
Despite the efforts of the Arab coalition, Israel emerged victorious, largely due to support from Britain and the United States, and expanded its territory beyond the original UN partition plan. This widened its borders and led to the displacement of a significant number of Arab inhabitants.