The Wehrmacht.

The United States Air Force, Strategic Air Command, specifically, and/or the former Soviet Strategic Rocket Forces (both now operating under new names, if I remember correctly). Either makes the Mongols and Wehrmacht look like delinquent four year olds, in terms of what they could do.

when i said the mongol army i meant the modern day army,as a infantry battalion are posted to iraq at the moment they do look pretty aggresive

Let's leave strategic nuclear forces out of it. I think, if you do, it's hands down the Wehrmacht, if we meaned feared by its enemies anyhow.

The Teufel Hunden

I'd have to go with the Wehrmacht as well, for an all around feared fighting platform. My own biased opinion would put the Australian army from World War I up there as well. Ain't too many armies want to be on the end of an ANZAC bayonet charge back then.

For Aussies - Drunked Collingwood (AFL) supporters and Caterbury Bulldog fans. I'd have to agree on the Wehermacht - it took a lot of bloodshed and a huge strategic victory (Stalingrad) to convince everyone that they could be beaten, and they still fought to the last (in Strategic terms anyway). Also considering the time and resources used creating ways to stop them, I'd put in the Red Army (in Europe). Pucka

I'd actually go the Huns for the sheer terror they inspired in people.

I think we need to set a guidline here. The post heading does say modern army. Yes the Huns were feared but are they modern? Lets keep this from 1900 onwards. We've had more than enough wars since then to keep everyone happy. Just on the Red Army, yes they were feared if you were a retreating German soldier from 42-43 onwards but were the Finnish ever scared of them? Especially in the first winter war it was the Red Army that was scared of the Fins

rather than most feared, isn't the issue one of most respected, ie in capability, in efficiency, bravery, perseverance. and then it can become theatre or even battle specific. eg fins in ww2, turks in ww1, gurkhas, sikhs, the afrika korp in it's early years. conversely, it can be one of professionalism. but as an issue of "fear", the russians in ww2 would have had to have been in a "top X" list. after all, there were western generals who wanted to cap them in 1944-45 as they saw them as the new demon hordes..