Most brutal time preriod for war?

So I have been pondering this for some- time. What time period do you reckon would be considered the most brutal/most difficult: medieval, pre modern (napoleonic wars and such) or modern. Now most people when asked this immediately jump to figures of casualties or fatalities, but thats not really what I am after. i want to know what you reckon would be more horrible, dofficult, horrendous on the average soldier: past- time war fare with close physical contact and horrendous wounds yet maybe with less constant battle or modern warfare with constant threat in your throat and bullets ripping yoiu up like nobodies bysuness? So what would you reckon is/was easier to live through or ope with?