Despite budget cuts and a reduction in size, the US has maintained its position as the world's strongest military, according to a report on globalization from Credit Suisse.

While the US is still far and away the world's top military superpower, Russia and China are its closest rivals. Canada, however, is the weakest of the twenty countries on the list. 

Credit Suisse acknowledged the difficulties of determining comparative military strength in its report. To provide a benchmark, the report assigns weighted values for six variables before tabulating a final score.

The factors under consideration for military strength and their total weights are: number of active personnel (5% of total score), tanks (10%), attack helicopters (15%), aircraft (20%), aircraft carriers (25%), and submarines (25%). 

The ranking defines military might in purely quantitative terms and does not account for the actual quality of the arms and training that the militaries may have. As such, the placement of some countries on the list may come as a surprise. 

The world's 20 strongest militaries are below.