Taking 1/2 marathon time to next level!

[Deleted User]

Hi all. Right, so I did the 2011 Sheffield half marathon. With little long distance training ( think the furthest I'd actually run was 6/7 miles) and came in at 1hr27, and actually really enjoyed it. I promised myself to do more long distance after that but didn't. A couple months after that I joined the Marines then due to family came out about 10 weeks ago so have been keeping myself fit. 

 Now I am keen to really try and get into my running. From an experienced runners point of view, do you think it would be possible , whilst keeping to a training regime like the 1/2 marathon ones on here that maybe by mid 2013 could maybe start hitting sub 1hr20 half marathons-maybe even closer to 1.15? Any training tips/advice much appreciated. Thanks