Hello kawann & welcome to the forum
I'm sorry to hear this kawann, if you have truly deleted your iPhoto Library from your Mac's internal HD and the only backup of these photos are on your stolen ext HD, then AFAIK, there's very little you can do unless you are using Time Machine which is a Leopard feature where you can revert to an earlier version of your internal Hard Drives contents.
I hope there's a chance you can retrieve your stolen HD ...
ALL I can think of at this time to sort of save your library is this.
Using the slider in the iPhoto Library View, slide it all the way to the right so the photo thumbnails are at their largest.
Using the Screenshot method
( shift + Command ( ⌘) + 3), capture each Library window as you scroll downwards ... this will take some time depending on how many photos you had.
Here's an example, I took a screenshot of my iPhoto Library with the app window fully maximise and with the thumbnails also at their max size:
Click for full size -
Uploaded with plasq's Skitch
Of course, this is sub-optimal and who knows how long it could take ... but at least you will have some semblence of your lost photo collection.
It's a good idea to have 2 backups ... I know I sound like a parent ... but hindsight is a powerful tool ... and hang on ... I AM a parent