This has probably been proposed in one form or another, but I'm too lazy to search. Again Insomnia causes random ideas in my brain...
Attrition attacks:
Any units not making any combat moves can declare an attrition attack. Attrition attacks are made by one or more territory into a bordering territory. An Attrition attack represents the continual struggle on the border between hostile forces. To make the attack add the number of attacking units and divide by 6(round up). Roll that many D6. The defender does the same. Dice rolls hit on a 3 or less.
Example:
German has 9 Inf, & 2Arm in West Russia
Russia has:
Karelia 3Inf
Archangel 3Inf
Russia 7Inf, 2 Arm, 2 Ftr, 1Art
Caucasus 6Inf 2 Arm 1 Art
Russia declares attrition attack against West Russia and rolls 5 dice and Germany rolls 2.
Russia:

Rolls: 5@3; Total Hits: 1
5@3: (5, 5, 6, 2, 5)
Germany:

Rolls: 2@3; Total Hits: 1
2@3: (2, 5)
Any hits are removed and the attack is over. This attack enables a defending player to inflict damage without compromising his defensive structure.