Yes, “you have lost” is present perfect and describes that the loss occurred at some unspecified point in time before. It can also describe a loss which effects can still be felt in the present.
The implication is that OP is convinced that Ukraine has no chance of holding their lines, as you correctly pointed out earlier.
Are you implying Ukraine has lost the war? That’s just not true, they still hold territory that according to Putin is part of Russia
No, I think they’re just responding to the headline.
“you have lost” is past tense
Yes, “you have lost” is present perfect and describes that the loss occurred at some unspecified point in time before. It can also describe a loss which effects can still be felt in the present.
The implication is that OP is convinced that Ukraine has no chance of holding their lines, as you correctly pointed out earlier.