WASHINGTON, July 1 (UPI) -- The delivery of six Russian Hind Mi-35 helicopters to Indonesia this month is neither a large arms deal nor an unprecedented one -- but it is still a highly significant event.

For the deal is just a small part of a huge $1 billion plus arms deal that then-Russian President and current Prime Minister Vladimir Putin nailed down last year.

Within that overall package, Russia is also buying three Sukhoi Su-27SKM and three Sukhoi Su-30MK2 aircraft. This too is not entirely unprecedented. The Indonesian armed forces are already operating two Sukhoi Su-27 SKs and two Sukhoi Su-30 MKs.

The key reason for the deal is that Russia is virtually giving the arms away free. Indonesia does not even have to start paying for them for another 15 years, and it has been given exceptionally easy credit terms. With its soaring revenues from oil and gas exports, the Kremlin can certainly afford to be generous when it is buying major strategic influence and supplanting the United States in an arms market that has been an almost exclusively American preserve for more than four decades.

However, the nature of Indonesia's unique security problems makes the nature of the Russian weapons offered to it exceptionally attractive.