Milliy iqtisodiyot nazariyasi "madaniy himoya" tushunchasi bilan bog'liq bo'lib, bu tushuncha og'ir sanoat nazariyasidan kelib chiqadi. Milliy iqtisodiyot nazariyasining tarafdorlari millat iqtisodiy o'sishining siyosiy kuch, shuningdek, iqtisodiy kuch bilan ta'minlashga qaratilishi kerak, deb hisoblaydilar. Ularning fikricha, har qanday mamlakatning o'sishi uch bosqichdan o'tadi: chorvachilik/qishloq xo'jaligi bosqichi, qishloq xo'jaligi/sanoat bosqichi, so'ngra qishloq xo'jaligi/sanoat/savdo bosqichi. Mamlakat dengiz floti, mustamlakalar va turli malakalarga ega aholiga ega bo'lmaguncha, haqiqiy kuchga erisha olmaydi. Bundan tashqari, ishlab chiqarish kuchlari va iqtisodiy o'sish uyg'unlikda bo'lishi zarur, bu esa siyosiy kuchning asosiy sharti bo'lib xizmat qiladi. Ular, shuningdek, xalqaro iqtisodiy aloqalar erkin raqobatdan foyda ko'rishi mumkin bo'lsa-da, bu barcha raqobatlashuvchi mamlakatlarning o'z kuchlarini rivojlantirishda kamolotga erishishiga bog'liq bo'lishini va bunday rivojlanishni rag'batlantirish uchun sanoatni himoya qilish kerakligini ta'kidlaydilar. Qishloq xo'jaligiga kelsak, u hech qanday himoyadan foydalanmasligi va barcha turdagi mahsulotlarni cheklovsiz va shartsiz eksport qilishga ruxsat etilishi, ularning narxlari esa erkin bozorga ko'ra belgilanishi kerak. Shunday qilib, milliy iqtisodiyot nazariyasi mohiyatan sanoatga yo'naltirilgan bo'ladi. Unga ko'ra, kuchli bo'lishga intilayotgan millatlar qishloq xo'jaligi bosqichidan sanoat bosqichiga o'tishga intilishlari kerak, chunki qishloq xo'jaligi mamlakatida ishlab chiqarish kuchlarining, ya'ni ishchi kuchining katta qismi, shuningdek, tabiiy resurslarning, ya'ni xom ashyoning katta hajmi ishsiz va o'zlashtirilmagan holda qoladi. Shuning uchun ishchi kuchi va tabiiy resurslarga sarmoya kiritish maqsadida qishloq xo'jaligi bilan bir qatorda sanoat dasturi ishga tushirilishi kerak. Iqtisodiyotini faqat qishloq xo'jaligiga asoslagan mamlakat, qishloq xo'jaligi/sanoatga asoslangan mamlakatda bo'ladigan iqtisodiy imkoniyat va turmush darajasiga ega bo'lmaydi. Milliy iqtisod nazariyasi mamlakat iqtisodiy jihatdan o'z oyog'iga tura olishi uchun qishloq xo'jaligi bilan birga sanoatning mavjud bo'lishini zarur qiladi. Shuning uchun milliy iqtisod tushunchasi aslida sanoatga protektsionizm nazariyasini qo'llaydi, ya'ni faqat sanoat importi va eksportiga tegishli cheklovlar va bojlarni joriy etadi, shu bilan birga qishloq xo'jaligiga erkin savdo nazariyasini qo'llab, uni har qanday savdo cheklovlaridan xoli qiladi.

The theory of national economy is linked to the concept of “cultural protection” derived from the theory of heavy industry. The champions of the theory of national economy deem that the economic growth of a nation must aim at providing her with political power as well as economic power. They deem that the growth of any country would undergo three stages: The pastoral/agricultural stage, the agricultural/industrial stage, then the agricultural/industrial trading stage. A country would not achieve real power unless she acquired a navy, colonies and populations with various skills. Furthermore it would be essential for the productive forces and economic growth to be in harmony, and this would serve as a fundamental condition of political power. They also deem that although international economic ties would benefit from free competition, this would depend on all competing countries reaching perfection in developing their powers; and in order to stimulate this development, industry must be protected. As for agriculture, it would not enjoy any protection and it would be permitted to export all kinds of produce without restriction or conditions, and their prices would be set according to the free market. Therefore, the theory of national economy would be in essence industry orientated. It states that the nations who aim towards being powerful should be eager to pass the agricultural stage to industry, because in the agricultural country, a large size of the productive forces i.e. the workforce, as well as a considerable size of the natural resources i.e. the raw materials, would remain unemployed and unexploited. Therefore, in order to invest in the workforce and the natural resources, an industrial programme should be initiated alongside agriculture. A country who establishes her economy solely based on agriculture would not possess the economic capability and the standard of living which an agricultural/industrial based country would have. The theory of national economy necessitates the presence of industry alongside agriculture in order for the country to be able to stand on its own feet economically. Therefore, the concept of national economy in fact applies protectionist theory on industry, thus imposing the appropriate restrictions and tariffs exclusively on industrial imports and exports, whilst at the same time, it applies free trade theory on agriculture making it free of any trade restrictions.

Islam rejects this theory, because leaving foreign agricultural trade free of control means that the State would not control the foreign trade of agricultural products. This is forbidden, for the State organises every agricultural, industrial, or other commodity that enters or leaves the country. It could ban the export of some commodities while permitting the export of others. It would deal directly with the issue of belligerents and traders under treaty, while choosing merely to supervise its own citizens. As for the State's interference in industrial matters in accordance with the country's interest and in order to boost the economy, this would form part of its duty to manage the Ummah's affairs, and this is commanded by Islam. However, all of this would be restricted by the interest of the Da'wah (the call to Islam), together with industrial development, i.e. not merely industrial development for its own sake. This demonstrates that, although the theory of national economy has, in parts of its industrial vision, aspects identical to those that are part of the management of the Ummah's affairs which Islam approves, such aspects contradict Islam because they are not linked to the interests of the Da'wah for Islam. Overall, the whole theory contradicts Islam due to the total freedom given to agriculture, and therefore Muslims would not adopt such a theory.

Islam is averse to such a theory, because leaving the foreign agricultural trade free of control means that the State would not control the foreign trade of agricultural products. This is forbidden, for the State organises all agricultural, industrial, or any other commodity which enters or leaves the country; she could ban the export of some commodities, while permitting the export of others. She would deal directly with the issue of belligerent and traders under treaty, while opting to merely supervise her own citizens. As for the State’s interference in industrial matters in accordance with the country’s interest and in order to boost the economy, this would form part of her duty to manage the Ummah’s affairs and this is commanded by Islam. However, all this would be restricted with the interest of the Da’wah (campaigning for Islam), together with the industrial development, i.e. not just for industrial development. This demonstrates that, although the theory of national economy has, in parts of its industrial vision, identical aspects to those which are part of the management of the Ummah’s affairs that Islam approves of, such aspects contradict Islam because they are not linked to the interests of the Da’awa for Islam. Overall, the whole theory contradicts Islam due to the total freedom given to agriculture, therefore Muslims would not adopt such a theory.