No, it isn't wrong. To say that something is of short duration means that it doesn't last long.
However, the sentence is awkward and has missing words. Telegrams often leave out unimportant words to save money. It's also missing context, which makes it hard to explain. So, let's put in the entire message, which (you? someone?) provided in a question elsewhere:
We stated we believe this would put you in impossible position, as conversations based upon 15 January drafts as now modified, but excluding alternative section on method of payment and the concession on the matter of interest payments, would be certain to be of extremely short duration.
Now, let's put in the missing words, and some punctuation:
We stated that we believe this would put you in an impossible position, as conversations that are based upon the drafts of 15 January as they are presently modified, but excluding the alternative section on the method of payment, and the concession on the matter of interest payments, would be certain to be of extremely short duration.
Here are the things that can be inferred from the sentence:
- There is a negotiation taking place.
- A tentative agreement was reached, and put in writing on 15 January (a "draft" is a written document that is subject to change).
- The negotiator has been asked to attempt to alter the agreement in two ways:
a. Remove the alternative method of payment.
b. Remove the concession on interest payments.
- If he tries, he won't get very far.
- So, trying would put him in an impossible position.
Now, The main point of the sentence is this:
Conversations based on [all of this stuff] would be certain to be of extremely short duration.
This is saying that any discussion of items 3a and 3b would be a very short one, because the other side wouldn't want to discuss them at all.