Why did the united states become involved in the korean war?

Why would the free rider problem prevent a private business from investing in the building of a city sidewalk?

Why was the bill of rights refered to as the anti-federalist legacy?

Which suggests the most critical aspect of the peak oil theory? 1) controversy rages over rumors that the fracking lobby in washington has influenced the statistics. 2) supporters and critics argue endlessly over the rate of extraction and shape of the bell curve. 3) saudi arabia will soon have to begin fracking, leading to protests and further destabilization. 4) a new oil discovery means a fresh peak cycle, making that region the target of aggressors.