Correct answer: Colombia had raised the price for the rights to build the Panama Canal.
Details:
As reported by the Office of the Historian of the United States: "President Theodore Roosevelt oversaw the realization of a long-term United States goal—a trans-isthmian canal" across the Isthmus of Panama. With Teddy Roosevelt in the White House, in 1902 the US Senate approved the building of a canal through Panama. Roosevelt's Secretary of State then went to work to arrange a treaty with Colombia (then in control of the Panama region). When Colombia ended up rejecting the US's offer because they thought the financial offer too low, President Roosevelt sent US naval warships to support the cause of Panama's independence from Colombia. After Panama achieved independence (with US support) in 1903, the new country, the Republic of Panama, agreed to treaty terms with the US for the building of the canal. The Panama Canal was completed in 1914.
ONe large one is that a ruler can not rise to power without a consensus of other people in the government and the public. A dictatorship is nearly impossible with a representative democracy.
