on my doorstep 人の家の軒先で

on my doorstep は人の家の軒先で、人の家の前で、人の縄張りのすぐ近くで、、という意味です。 1:08 analysts say Kim also wants to fend off the threat he perceives from his principal enemies who've just wrapped up a massive military exercise on his doorstep.

North Korea: We can hit 'America bastards'
https://www.youtube.com/watch?v=mnIY6AE4m6E  42;08 everybody shared the benefit of food grown in this marvelously fertile region, and sourced from the plentiful Mediterranean, which in those days was right on their doorstep. 目と鼻の先
Pompeii - Life and Death in a Roman Town ( Mary Beard )
https://www.youtube.com/watch?v=r44zIi1I3yw  2:13 one week before the wedding, her designer gown arrives on her doorstep.
Website Rents Designer Bridesmaids Dresses for Less
https://www.youtube.com/watch?v=uJSjcZ9beO4  0:48 people prepare to live on the doorstep of Fukushima Daiichi with its three crippled reactors. 住民は三基の原子炉が溶解した福島第一原発のそばに住む覚悟が出来ている。　
Japan attempts to revive nuclear ghost town
https://www.youtube.com/watch?v=Dn4OjSdQGw4  1;22 the chances are that a photographer or a reporter would turn up on your doorstep before a policeman. もし僕や恋人になにかあったら警官よりもさきにカメラマンやレポーターが家に来る可能性のほうが高い。
UK phone-hacking victims condemn intrusion

参考リンク
http://bridge-english.blogspot.jp/2010/06/blog-post_4760.html  目と鼻の先を英語でなんと言うか？
http://bridge-english.blogspot.jp/2009/07/blog-post_3109.html  目の前を英語でなんと言うか？
http://bridge-english.blogspot.jp/2011/02/in-your-neck-of-woods.html  in your neck of the woods

練習問題解答
a-9703 even as the crisis on his own doorstep deepened
b-1554 on its doorstep
b-3451 right on NATO's doorstep