Every NATO member has somewhat different defense plans but the one thing all have in common is the ancient threat from the Russian Empire. While the larger NATO members (U.S., Britain and France) have nuclear weapons, the smaller ones have to be more creative in dealing with the Russian threat. The smallest and most exposed members of NATO are the three Baltic States: Estonia, Latvia, and Lithuania. Together these three nations have a population of only six million. Russia has over 140 million and an increasingly open desire to regain its valuable Baltic territories and other recently (1991) lost portions of the empire.
The Baltic States have long been fought over because, like most coastal areas, the Baltic States were always more prosperous than inland areas because of seaborne trade and fishing, in addition to farms inland. Currently the per capita GDP of the Baltic States of twice that of Russia and a third higher than Poland (which has a large Baltic coastline but also a lot more inland area). Poland, Sweden and Germany were a threat to what is now the Baltic States over the last thousand years, but since the 1700s another threat has been Russia, and still is.
Once the Soviet Union fell apart in 1991 many Russian neighbors feared a revival of the traditional Russian aggression and empire building. Thus in 2004 Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia joined NATO, putting parts of the former Soviet Union (Estonia, Latvia and Lithuania) within NATO and on Russia’s border. Many Russians do not like this, for Russian policy since 1945 has been to establish a "buffer" of subservient (preferably Russian occupied) countries between Russia itself and the rest of Western Europe (especially Germany). This attitude is obsolete in a practical sense but old habits die hard.
In the 1990s the new post-communist Russian government said it was willing to work with NATO in areas of mutual benefit but that did not work out. Now there is a state of undeclared war between Russia and NATO. These new NATO members are more worried about the renewed Russian aggression than the original NATO members (the U.S. and Western Europe). The nations of “east NATO” are asking for more presence by troops from “west NATO.” Some of the eastern members (especially Poland and the Baltic States) have called for the permanent basing of U.S. troops on their territory. The smaller states Estonia, Latvia, and Lithuania believe Russia could overrun them in two days and senior NATO military commanders openly agree. Russia considers such talk more evidence of NATO aggression against Russia. The Baltic States have heard this kind of talk from Russia before and want to avoid the usual outcome.
All three Baltic States have adopted similar defense plans based on that long used by Switzerland (and later Sweden and Israel). This “total war” mobilization system expected every citizen to be prepared to resist an invader. In the last century this has meant conscription of all able males (and even some females) for a year or so of training followed by decades of service in a reserve. The Baltic States have eliminated conscription and depend on fear (of the Russians) to obtain enough volunteers for the active duty forces and the much larger reserve. Beyond that all citizens are constantly reminded of how they can all resist an invader (Russia is the only likely one as the Germans, Poles and Swedes have abandoned imperial ambitions).
In light of this most Latvians accepted the new “total mobilization” policy which provides more opportunities for all citizens to participate. The voters would not revive conscription but so far there has been sufficient willingness by military age men (and many women) to join or otherwise support the largely part-time military. There are now voluntary programs in high schools where students can receive basic military training. Other countries have found that programs like this enable many potential recruits to see if they have any aptitude and interest in this sort of thing. Many find that they do and those who are not really good at it discover that as well. The military is also establishing a Summer Training program in which students can volunteer for several weeks (or more) of full time training. There is now money for National Guard units to conduct training that can get expensive (like how to obtain lumber and other materials locally to build roadblocks and other obstacles). There is also more money for part time soldiers to practice their marksmanship and using other weapons (grenades, mortars, anti-tank rockets, explosives in general).
The current Latvian armed forces are quite small. There are 4,600 active duty troops, 11,000 reserves (former active duty men who can be mobilized in wartime) and 8,000 in the National Guard. While the reserve troops are not very active at all, the National Guard is another matter. The National Guard proved so popular that it is being allowed to expand to 12,000 (by 2027). Many of the troops who complete a term of active service volunteer to join the National Guard rather than just be a name on a mobilization list in the reserves. The Latvian military is now the classic type that Switzerland pioneered; a small number of full time troops that exist mainly to train and support the 20,000 part time personnel.
The Latvian National Guard is more like the American National Guard in that it devotes a lot of its training and organization to dealing with natural or other emergencies in a specific part of the country. But the Latvian personnel are armed and improving their military skills enthusiastically and often on their own time. Latvia recently decided to harness this enthusiasm by devoting more of the military budget to obtaining more equipment and expensive training. This additional investment is intended to produce some units in each National Guard battalion with the ability to activate and move much more quickly than the rest of their battalion.
Since Latvia joined NATO in 2004 they have had ample opportunity to test their system by mobilizing reserve and National Guard units more frequently for training, often with other NATO troops. Because Latvia went all-volunteer in 2005 they have no problem getting troops to go overseas on peacekeeping duty. Meanwhile Estonia and Lithuania have revived conscription and Latvia will monitor how that goes and that will influence future efforts to revive it in Latvia. But so far Latvians would prefer to keep it voluntary.
Like the other two Baltic States Latvia is tiny (population two million) and 0nly 61 percent of that is ethnic Latvian while 25 percent is ethnic Russian. Defense spending is only $715 million dollars a year (two percent of GDP). Latvia, like the other Baltic States planned to increase defense spending to two percent of GDP by the end of the decade and was able to do it by 2018. Even so that is not a lot so the Latvians are depending on the mobilization of the entire population to resist.
There is also more sharing of ideas with the other Baltic States. For example in late 2016 neighbor Lithuania issued a 75 page “how to survive another Russian occupation” manual for its citizens called; "Prepare to survive emergencies and war." Latvia has adopted that approach. All three Baltic States have plenty of experience with being invaded and occupied by Russia and wants to remind its citizens what works, especially now that the Baltic States have a mutual defense treaty with the United States and all other NATO members. Latvia has a Mobilization Law which covers all this and the bit of legislation is in a constant state of upgrade and revision.
The “prepare to survive” guide provides tips that resonate with most Russian neighbors. Thus the guide tells how to behave when dealing with the invader while also spying on the occupation force. The manual provides illustrations and description of most Russian weapons and details of how the Russians use secret police, local informants and special operations troops to try and control an occupied population. The manual also points out that Russia will send in agents (or activate ones it has already recruited) before an invasion and provides tips on how to detect the presence of these agents, especially in preparation for an imminent invasion. All three Baltic States have issued this type of document along with Sweden and Finland.