JAWS should indicate that the sending nation's name is also a link. That's the quickest was to respond to a telegram, as it takes you directly back to the nationpage in question. The telegram box is a standard "post" form, so I would think that JAWS would allow you to switch the focus into the form to send messages.
Here's the code from your nationpage as I see it:
<form method="post" action="http://www.nationstates.net/cgi-bin/index.cgi/">
<input type="hidden" name="page" value="send_message">
<input type="hidden" name="recipient" value="gatchalian">
<input type="hidden" name="chk" value="JGoj9ykXBxoug">
<p>Want to wire a telegram to Gatchalian?
<pre>To: Gatchalian From: Frisbeeteria</pre>
<textarea name="message" rows="8" cols="60" wrap="soft"></textarea>
<br>
<input type="submit" value="Send!">
</form>
You can also go to The world (http://www.nationstates.net/cgi-bin/index.cgi/page=world) link (on every game page), scroll to the bottom, and type any nation name or region name to take you directly to your target nation.