Interesting historical overview of US foreign policy. Since 1776, the country deliberately avoided any commitment towards wars outside its interest. Neither Napoleon nor Bismarck did trigger US intervention. All started to change when Teddy Roosevelt started an imperialist policy, i.e. the colonisation of The Phillipines. But Woodrow Wilson was the true master of interventionism. Against the will of the American people, he got the USA involved into WW I, leading to hundreds of thousands of (unnecessary) American body bags. Less than 25 years later, Franklin Roosevelt led USA into another world war, although no Axis power was strong enough to threaten the country. E.g. Hitler Germany had nor the means nor the will to invade the American continent.
Buchanan is more in favour of the American efforts in Europe to keep it safe from communism. He is especially sympathetic towards president Reagan who brought the Soviet Union to its knees with little or no violence.
Since then, both Bush sr. and Clinton started conflicts outside America's hemisphere: Haiti, Serbia, Iraq,... Although the book is dated 1999, the author is already wary of neo-conservative politics. No hegemonist policy like Bush jr and no globalist policy like Obama, but Realpolitik like the 19nd century American politicians or their European peers (Metternich, Bismarck,...). USA should only watch its own interest.
To end with a striking statement: US foreign policy should not be dovish or hawkish, but like an eagle, i.e. a powerful, keen sighted, high-flying, remotely perched and the eminently well-protected bird.