If you add 2 or 3 hundred years to American history, I imagine they would have a few more wars under their belts. Britain didn�t have many of the delightful commodities that were available in mainland Europe and beyond and so had to go and get them. One way to do this was by conquering nations, a precedent set by the Roman Empire, the Babylonians, Mongol, Persian, Umayyad, Byzantine, Ottoman, French, Spanish, Russian etc etc. Under George V in 1922, the British Empire encompassed more land mass than any previous empire or any since.
In fact, because of the Spanish Empire's territories around the globe, it was often said in the 16th century that "the sun never sets on the Spanish Empire." This phrase was later applied to the Russian Empire and British Empire.
In terms of colonialism, the European precedent was set by Portugal and Spain in the 15th C. Britain finally followed suit in the 17th C.
Incidentally the Falklands war was caused by the illegal invasion and occupation of sovereign territory by a foreign hostile force. No doubt you would expect �the British� to get involved should a foreign nation decide to goose step into Scotland.