Not necessarily...
1) A surprising number of DVD players in the UK have a high-definition VGA output mode, enabled by "secret" menus. It is unlikely this would be the case in the US, as it is done over the SCART socket, which you don't have on US-model DVD players. But I know there are models that sell in the US that are international models WITH this connector (the KiSS range, for example).
2) There are DVD players available with a DVI output. This is a digital monitor connection that is only really common on TFT screens, but if you have a DVI monitor, you could use one of these.
3) The last, easiest, and possibly cheapest solution is to buy a TV adaptor for your monitor. These have SVHS and Composite video inputs, a TV tuner and a VGA connector to hook up to your monitor. My bro uses one of these with a 19" Sony panel and it looks great.