OK CJ. Thanks for the answer but I am a bit confused. Let me restate your explanation in my words. Please correct me if I am wrong.
As you said that you like to match the tenses, so this means that since in the first clause of the sentence, the author has used simple present and is talking about a problem currently faced by the committee, therefore in the subsequent clause where it describes what the committees did in the past should have some relavance with the present. Now simple past only talks about an event that took place in the past (as you said a past history - don't you think
past history is redundant) so using it here will have no bearing about what is or should happen in the present. Present Perfect on the other hand talks about a duration from past up till now so it surely has a bearing upon what is or should happen in the present.
What I didn't understand is you philosophy of simple past and present perfect and their visibility and vagueness and standing beside wall and thick wall...... I don't know. Please explain what does the vageness and clarity has to do with the sentences and (most importantly) how whould I know that this particular sentence should be vague or clear.
GB