Then you'll certainly be familiar with some citation or documentation of evidence? I'm curious to see some.
1. It's known publicly that nation states as well as criminal organizations are deflecting Internet routes. There are numerous reports of such cases; these cases aren't that hard to find since BGP information is (mostly) public. A few published examples:
- Russian network "Rostelecom" hijacks sites of financial services: https://arstechnica.com/information-technology/2017/04/russi...
- Global Large scale BGP hijacks in 2013, some through "Rostelecom": https://arstechnica.com/information-technology/2013/11/repea...
- Spammers use BGP to announce fake IP addresses to spam yahoo mail users: https://ripe72.ripe.net/presentations/45-Invisible_Hijacking...
- Traffic to UK organization that deals with nuclear weapons hijacked using BGP to the Ukraine: http://hub.dyn.com/dyn-research/uk-traffic-diverted-through-...
- BGP hijack of bitcoin miners: https://bgpmon.net/the-canadian-bitcoin-hijack/
- "Hacking Team" (Italian company selling spyware to law enforcement) helps Italian police perform BGP hijack: https://arstechnica.com/information-technology/2015/07/hacki...
- Chinese hijack of US military an governmental networks (2010): http://www.theregister.co.uk/2010/11/17/bgp_hijacking_report...
2. There are known attacks against routing protocols which aren't BGP (e.g. OSPF, Black Hat 2011) and against routers (see CVEs for CISCO IOS).
3. Routing changes that happen within an autonomous system leave a much smaller footprint compared to BGP.
4. Nation states are known to have an interest in direct access into routers:
- Suspected NSA example: http://www.theregister.co.uk/2015/09/15/compromised_cisco_ro...
- Suspected Chinese example: http://www.abovetopsecret.com/forum/thread350381/pg1
5. Network connect to each other (mainly) in central exchange points. In these exchanges networks can pay for a direct point-to-point connection from network to network, or use open peering through a layer 2 switch that aggregates connections from dozens or hundreds of different networks at once (Example: https://www.de-cix.net/en/de-cix-service-world/globepeer). Hundreds of networks use these switches with very little visibility. Everyone can talk to everyone else on the same switch without leaving a trace. If a router connected to such a switch is locally configured to forward traffic to some other router on the same switch, it can do so regardless of BGP routing or any common sense.
Are you saying that Russia and China should be worried?
An attacker compromises a router (there are known vulnerabilities and back-doors) or gains leverage over a technician authorized to configure routers in some network. The attacker then manually changes the router's local routing table to forward packets to specific destinations through a different path. In such cases, the BGP path and announcements look absolutely fine and you'd need to look at the actual path at the data plane level to detect that something is wrong.
This is often done in big exchange points where many networks interconnect. These are places in which routers from major western countries can sit basically side-by-side with routers from Russia and China.
This isn't a paranoid fantasy by the way, I work for a company that monitors these kinds of attacks for a living.